请用英文具体介绍奥运会的一项运动项目

请用英文具体介绍奥运会的一项运动项目
请用英文具体介绍奥运会的一项运动项目

请用英文具体介绍奥运会的一项运动项目
volleyball
Volleyball is an Olympic sport in which two teams separated by a high net use their hands, arms, or (rarely) other parts of their bodies to hit a ball back and forth over the net. Each team is allowed three hits to get the ball over the net to the other team. A point is scored if the ball hits the ground in the opponents' court, if the opponents commit a fault, or if they fail to return the ball properly.

Volleyball gameVolleyball can be a very active sport that can be an excellent source for aerobic exercise. It also helps players improve their hand-eye coordination and the ability to override the instinctive desire to dodge a fast-moving object such as a ball.
History of the game
On February 9, 1895, in Holyoke, Massachusetts, William G. Morgan a YMCA physical education director, created a new game called Mintonette as a pastime to be played preferably indoors and by any number of players. The game took some of its characteristics from tennis and handball. Another indoor sport, basketball, was catching on in the area, having been invented just ten miles (sixteen kilometres) away in the city of Springfield, Massachusetts only four years before. Mintonette (as volleyball was then known) was designed to be an indoor sport less rough than basketball for older members of the YMCA, while still requiring a bit of athletic effort.
The first rules, written down by William G. Morgan, called for a net 6 feet 6 inches (1.98 metres) high; a 25 × 50 foot (7.6 × 15.2 metre) court; and any number of players. A match was composed of 9 innings with 3 serves for each team in each inning; and no limit to the number of ball contacts for each team before sending the ball to the opponents’ court. In case of a serving error, a second try was allowed while a ball hitting the net was to be considered a foul (with loss of the point or a side-out) — except in the case of the first-try serve. To protect the fingers of the ladies, they were allowed to catch the ball and then throw it back into play.
After an observer noticed the volleying nature of the game at its first exhibition match in 1896 played at the Springfield YMCA, the game quickly became known as volleyball (originally spelled as two words). Volleyball rules were slightly modified by the Springfield YMCA and spread around the country to other YMCA locations.
An international federation, the Fédération Internationale de Volleyball (FIVB), was founded in 1947, and the first World Championships were held in 1949 for men and 1952 for women. Volleyball was added to the program of the Olympic Games in 1964, and has been part ever since. Beach volleyball became a FIVB-endorsed variation in 1986 and was added to the Olympic program at the 1996 Summer Olympics.
It was not until 1900 that a ball was made specifically for the new game, and the rules were not how we know them today. It took until 1916 for the skill and power of the set and spike to be introduced, and four years later a "three hits" rule and back row hitting guidelines were established. In 1917, the game was changed from 21 to 15 points. In 1919, American Expeditionary Forces distributed 16,000 volleyballs to their troops and allies: this provided a stimulus for the growth of volleyball outside the United States.
The first country outside the United States to adopt volleyball was Canada in 1900. The sport is now popular in Brazil, all of Europe (where especially Italy, Netherlands, Bulgaria and Serbia are major forces since the late Eighties), Russia, other countries including China and the rest of Asia, as well as the United States. The FIVB estimates that 1 in 6 people in the world participate in or observe indoor volleyball, beach volleyball, or backyard (recreational) volleyball.
See also Volleyball in the United States
Rules

Volleyball court
Equipment
The game is played on volleyball courts 18 metres long and 9 metres wide, divided into two 9 x 9 metre courts by a one-metre wide net placed so that the top of the net is 2.43 metres above the centre of the court for men's competition, and 2.24 metres for women's competition (these heights are varied for veterans and junior competitions). There is a line 3 metres from and parallel to the net in each team court which is considered the "attack line". This "3 metre" line divides the court into "back row" and "front row" areas. These are in turn divided into 3 areas each: these are numbered as follows, starting from area "1", which is the position of the serving player:
4 3 2
5 6 1
After a team gains the serve (also known as siding out), its members must rotate in a clockwise direction, with the player previously in area "2" moving to area "1" and so on, with the player from area "1" moving to area "6" (see also the Errors and Faults section).
The team courts are surrounded by an area called the free zone which is a minimum of 2 metres wide and which the players may enter and play within after the service of the ball. All lines denoting the boundaries of the team court and the attack zone are drawn or painted within the dimensions of the area and are therefore a part of the court or zone. If a ball comes in contact with the line, the ball is considered to be "in". An antenna is placed on each side of the net perpendicular to the sideline and is a vertical extension of the side boundary of the court. A ball passing over the net must pass completely between the antennae (or their theoretical extensions to the ceiling) without contacting them.
The volleyball is made of leather or synthetic leather and inflated with compressed air. It is round and 65-67 cm in circumference.
Game play
Each team consists of six players, three located in front of the attack line and three behind.
To get play started, a team is chosen to serve by coin toss. A player from the serving team (the server) throws the ball into the air and attempts to hit the ball so it passes over the net on a course such that it will land in the opposing team's court (the serve). The opposing team must use a combination of no more than three contacts with the volleyball to return the ball to the opponent's side of the net. These contacts usually consist first of the bump or pass so that the ball's trajectory is aimed towards the player designated as the setter; second of the set (an over-hand pass using wrists to push finger-tips at the ball) by the setter so that the ball's trajectory is aimed towards one or more players designated as the attacker and third by the attacker who spikes (jumping, raising one arm above the head and hitting the ball so it will move quickly down to the ground on the opponent's court) to return the ball over the net. The team with possession of the ball that is trying to attack the ball as described is said to be on offense.
The team on defense attempts to prevent the attacker from directing the ball into their court by having players at the net jump and reach above the top (and if possible, across the plane) of the net in order to block the attacked ball. If the ball is hit around, above, or through the block, the defensive players arranged in the rest of the court attempt to control the ball with a dig (a fore-arm pass of a hard-driven ball). After a successful dig, the team transitions to offense.
The game continues in this manner until the ball touches the court within the boundaries or until an error is made.
Errors and faults
The ball lands out of the court, in the same court as the team that touched it last, or the ball touches the net "antennas". The ball also may not pass over or outside the antennas even if it lands in the opponents' court1.
The ball is touched more than three times before being returned to the other team's court2.
The same player touches the ball twice in succession3.
A player "lifts" or "carries" the ball (the ball remains in contact with the player's body for too long).
A player touches the net with any part of his or her body or clothing while making a play on the ball (with the exception of the hair).
The players of one team do not manage to touch the ball before the ball lands in their half of the court.
A back-row player spikes the ball while it is completely above the top of the net, unless he or she jumped from behind the attack line (the player is however allowed to land in front of the attack line).
A back-row player attempts to block an opposing team's attack by reaching above the top of the net.
The libero, a defensive specialist who can only play in the back row, makes an "attacking hit", defined as any shot struck while the ball is entirely above the top of the net.
A player completes an attack hit from higher than the top of the net when the ball is coming from an overhand finger pass (set) by a libero in the front zone.
A player is not in the correct position at the moment of serve, or serves out of turn. This type of foul is related to the position currently occupied by the players (see the table in the Equipment section). When ball is served, players can place themselves freely on the field (e.g. a "back-row" player can be close to the net) so long as they obey the following rules: The area "1" player must be behind the area "2" player and to the right of the area "6" player. The area "6" player must be behind area "3" player, to the left of area "1" player and to the right of area "5". The area "5" player must be behind the area "4" player and to the left of the area "6" player. Symmetric rules must be respected by the front-row players (those in areas "2", "3" and "4").
When hitting, a player makes contact with the ball in the space above the opponent's court (in blocking an attack hit, this is allowed).
A player touches the opponent's court with any part of his or her body except the feet or hands4.
When serving, a player steps on the court or the endline before making contact with the ball.
A player takes more than 8 seconds to serve.[1]
At the moment of serve, one or more players jump, raise their arms or stand together at the net in an attempt to block the sight of the ball from the opponent (screening)5.
Notes: 1 If the ball passes outside the antennas on the first contact for the team, e.g. as the result of a bad pass or dig, a player is allowed to go after the ball as long as he or she does not touch the opponent's court and the ball travels back to his or her team's court also outside the antennas.
2 Except if a player blocks (touches a ball sent over the net by the opposing team, while reaching above the top of the net) a ball that stays in the blocker's side of the net. In such an instance the blocker may play the ball another time without violating the rule against playing the ball twice in succession. If the ball is touched during a block, that contact is not considered one of the team's three contacts.
3 At the first hit of the team, the ball may contact various parts of the body consecutively provided that the contacts occur during one action. Also, when a player touches the ball on a block, he or she may make another play on the ball.
4 Penetration under the net with hands or feet is allowed only if a portion of the penetrating hands or feet remains in contact with or directly above the player's court or centre line.[2]
5 Screening is only a fault if the players stand directly next to each other in a way that clearly impedes vision, and the serve is a low line drive over their heads. (This is a judgment call by the referee. Teams are generally given a warning before being sanctioned for screening.)
Scoring
When the ball contacts the floor within the court boundaries or an error is made, the team that did not make the error is awarded a point, whether they served the ball or not. The team that won the point is awarded the right to serve for the next point. If the team that won the point served the previous point, the same player serves again. If the team that won the point did not serve the previous point, the players of the team rotate their position on the court in a clockwise manner. The game continues, with the first team to score 25 points (and be two points ahead) awarded the set. Matches are best-of-five sets and the fifth set (if necessary) is usually played to 15 points. (Scoring differs between leagues, tournaments, and levels; high schools sometimes play best-of-three to 30; in the NCAA games are played best-of-five to 30.)
Before 1999, points could be scored only when a team had the serve (side-out scoring) and all sets went up to only 15 points. The FIVB changed the rules in 1999 (with the changes being compulsory in 2000) to use the current scoring system (formerly known as rally point system), primarily to make the length of the match more predictable and to make the game more spectator- and television-friendly.
The Libero
In 1998 the libero player was introduced internationally, the term meaning free in Italian; the NCAA introduced the libero in 2002. The libero is a player specialized in defensive skills: he or she must wear a contrasting jersey color from his or her teammates and cannot block or attack the ball when it is entirely above net height. When the ball is not in play, the libero can replace any back-row player, without prior notice to the officials. His or her replacements also do not count against the substitution limit each team is allowed per set, although the libero may be replaced only by the player whom s/he replaced.
The libero may function as a setter only under certain restrictions. If s/he makes an overhand set, s/he must be standing behind (and not stepping on) the 3-meter line; otherwise, the ball cannot be attacked above the net in front of the 3-meter line. An underhand pass is allowed from any part of the court.
Furthermore, a libero is not allowed to serve, according to international rules, with the exception of the NCAA women's volleyball games, where a 2004 rule change allows the libero to serve, but only in a specific rotation.
Other recent rule changes
Other rule changes enacted in 2000 include the introduction of the let serve which allows play to continue even if a served ball touches the net as long as it continues into the opponents' court. Also, the service area was expanded to allow players to serve from anywhere behind the end line but still within the theoretical extension of the sidelines. Other changes were made to lighten up calls on faults for carries and double-touches, such as allowing multiple contacts by a single player ("double-hits") on a team's first contact. From 2006 there are plans for trying new rule changes, such as having a second serve option when failing the first (as in tennis) or a second alternative libero in the team.
Skills
Competitive teams are supposed to master six basic skills: serve, pass, set, attack, block and dig. Each of these skills comprises a number of specific techniques that have been introduced along the years and are now considered standard practice in high-level volleyball.
Serve

Setting up for an overhand serve.
A player making a jump serve.A player stands behind the baseline and serves the ball, in an attempt to drive it into the opponent's court. His or her main objective is to make it land inside the court; it is also desirable to set the ball's direction, speed and acceleration so that it becomes difficult for the receiver to handle it properly. A serve is called an "ace" when the ball lands directly onto the court or travels outside the court after being touched by an opponent.
In contemporary volleyball, many types of serves are employed:
Underhand and Overhand Serve: refers to whether the player strikes the ball from below, at waist level, or first tosses the ball in the air and then hits it above shoulder level. Underhand serve is considered very easy to receive and is not generally employed in high-level competitions.
Sky Ball Serve: a specific type of underhand serve, where the ball is hit so high it comes down almost in a straight line. This serve was invented and employed almost exclusively by the Brazilian team in the early 1980s and is now considered outdated.
Line and Cross-Court Serve: refers to whether the balls flies in a straight trajectory parallel to the side lines, or crosses through the court in an angle.
Spin Serve: an overhand serve where the ball gains topspin through wrist snapping.
Floater: an overhand serve where the ball is hit with no spin so that its path becomes unpredictable. This type of serve can be administered while jumping or standing. This is akin to a knuckleball in baseball.
Jump Serve: an overhand serve where the ball is first tossed high in the air, then the player makes a timed approach and jumps to make contact with the ball. There is usually much topspin imparted on the ball. This is the most popular serve amongst college and professional teams.
Round-House Serve: the player stands with one shoulder facing the net, tosses the ball high and hits it with a fast circular movement of the arm. Usage of this serve in indoor volleyball is today restricted to a few Asian women's teams. The ball is hit with the palm of the hand, creating a lot of spin.
Pass

A woman making an underhand pass or bumpAlso called reception, the pass is the attempt by a team to properly handle the opponent's serve or "free ball". Proper handling includes not only preventing the ball from touching the court, but also making it reach the position where the setter is standing quickly and precisely.
The skill of passing involves fundamentally two specific techniques: underarm pass, or bump (“bacher” in European terminology), where the ball touches the inside part of the joined forearms or platform, at waist line; and overhand pass, where it is handled with the fingertips above the head and is common of setters.
Set
The set is usually the second contact that a team makes with the ball. The main goal of setting is to put the ball in the air in such a way that it can be driven by an attack into the opponent's court. The setter coordinates the offensive movements of a team, and is the player who ultimately decides which player will actually attack the ball.
As with passing, one may distinguish between an overhand and a bump set. Since the former allows for more control over the speed and direction of the ball, the bump is used only when the ball is so low it cannot be properly handled with fingertips, or in beach volleyball where rules regulating overhand setting are more stringent. In the case of a set, one also speaks of a front or back set, meaning whether the ball is passed in the direction the setter is facing or behind the setter. The setter usually stands about ⅔ of the way from the left to the right of the net and faces the left (the larger portion of net that he or she can see).
Sometimes a setter refrains from raising the ball for a teammate to perform an attack and tries to play it directly onto the opponent's court. This movement is called a "dump". The most common dumps are to 'throw' the ball behind the setter or in front of the setter to zones 2 and 4. More experienced setters toss the ball into the deep corners or spike the ball on the second hit.
Attack

An attack in progressThe attack (or spike, the slang term) is usually the third contact a team makes with the ball. The object of attacking is to handle the ball so that it lands on the opponent's court and cannot be defended. A player makes a series of steps (the "approach"), jumps, and swings at the ball.
Ideally the contact with the ball is made at the apex of the hitter's jump. At the moment of contact, the hit