His pants are red,mine is blue 为何前面复数,后面是单数

His pants are red,mine is blue 为何前面复数,后面是单数 blue his are pants these . are,pants,those,red,pretty,very怎么连词成句? His pants are out of style.out of style 划线提问.___ ___ ___ his pants? Mary's pants are red.(对划线部分提问)划线的是red His pants are blue(改一般疑问句） 句型转化 These pants are mine.My shoes are white.They don‘t have the same look.（同义句）This is his new ruler.（同义句）Are those your pants?（同义句）That is her dress.（同义句）The boy is tall.The boy in red is my brother The red pants are ten dollars.（How much开头）的提问 these pants are （white and red）对划线部分提问 The sweater is 88 yuan 划线 (88 yuan)that coat is red (red)they are their T-shirt (their)those are pants (pants)the price of the skirt is 60 dollars (dollars)The green shoes are dear.(the green shoes) whose pants are those? His pants are out of style 划线部分提问划线的部分是 out of style而且 要是 ____ ____ _____ his pants The person you are talking to puts his pants on one leg at a time Mary's pants are red.(对划线部分提问）划线的是red My favorite subject is history.划线的是history I want a red sweater and white pants.请对 a red sweater and white pants提问：_____ _____ you want?He buys a red bag for his mom.请对 a red bag提问：___ ___ he ___ for his mom? His red shoes are in the libaby.中文是什么 My shoes are red ,but his ________ pink . pants are these black howmuch 连词成句those bags are fifteen yuan 对划线部分提问 ____________i want a red sweater and white pants 对划线部分提问 _____________________________the black socks are $7.00 对划线