the students is busy for their exams；the students are having an english class.1、为什么第一句用is 第二句用are 同样是 the students开头2、the students是代表一类人吗?这个知识点我有点模糊了求指教

the students is busy ( )their exams适当的介词 the final examination is coming ,the students are busy---------[review] the lessons. The students in Grade 3 are busy revising __ their lessons A.is B.for C.wit h D.to The teacher is busy ______teaching. The students are busy doing some_____for the final exam.(review) The students are busy ___(listen) to the teacher. the students is /are look,the farmers are busy in the field ,and the rice is -i-- for harvestMany students work hard, they are -o----- about the future _____the students busy ____(help)the farmers___(pick) apples The students are busy with their homework 同义句转换 The students-----busy-----(get) ready for their exam now. The students are not busy this afternoon同义句 most.of.students.are.busy.cleaning.the.classroom求翻译 The students are busy leaning English 同义句 all the students are busy------(do) a lot of things. the students will go to Busy Street tonight(同义句） the students _ _ _ Busy street tonight 同义句转换.The students are busy learing English.The students are ( ) ( ) English. The library's study room is full of students _ for the exam A:busily prepared B:busy preparing C:busily prepare D:are busily preparing