People、water、air这些词后面为什么要加动词的第三人称单数.

People、water、air这些词后面为什么要加动词的第三人称单数. people cannot ( ) without air and water.(live) people can't live if there is not water or air people can't live ____ water or air 求词和理由!@ 句型转换:People will die if there is no air and no water.People ()()()air()water. People _______(can not live) with out air or water. 同义句转换 People will die if there is no air and no water.People ___ ___ ___ air ___ water. People can't live without water or air.同义句 People can't live ___ there _____ ___ water or air. People can't live without water or air.（改为同义句,每空一词）People can't live ( ) there ( ) ( ) water or air. sun air water earth air water fire Water-to-Air Cooler People can't live if there no water or air(改为同义句）. People can't live＿＿＿＿＿(with) water or air Most people had no idea how dirty our air and water were.翻译 people can't live without water or air为什么是or in ancient Chian,people used to b____ water over the fire in the open air people can use it to change the water into the air People cannot s without water or airPeople cannot s without water or air 代点字加点字