five students in my class have joined the youth league this term 中的have joined为什么要用这种时态呢（求解啊谢谢）

there are thirty-five students in my There are five students in our school There are thirty-five students in our class.中对 thirty-five students提问,怎么回答? Five people live in my home 对Five people提问 There are at ____ five hundred students in our school there are about five hundreds students in Grade One 改错 there are five hundreds students in his school 改错题 five students in my class have joined the youth league this term 中的have joined为什么要用这种时态呢（求解啊谢谢） There are fifty-five students in our class(对fifty-five 提问) There were five hundred students in our school last year.划线部分是five hundred,提问 I can see five students in the room.(对five提问) A taecher has five oranges in her basket. She gives them to five students. There are twenty students in my class.There are forty-five students in your class.My teacher corrects twenty student's homework every day .Your teacher has to correct forty-five student's homework.Your teacher has a ___________job to do than my teach Our class has forty-five students.（改为同义句） （ ）（ ）forty–five students in our class. There are _____ students in my class. there are same students in my class .He works in a university with over five thousand students .改同义句66.He works in a university with over five thousand students .He works in a university ____ ____ over five thousand students. 同义词改写There are five bananas in his box.----- ----- five bananas in the box.My aunt buys hamburgers for five dollars.My aunt ----- five dollars ----- hamburgers.