classes begin at ...和class begins at ...它们有什么区别?

Classes begin at eight. classes begin at enght.为什么classes classes begin at （eight）划线提问 classes begin at （eight）划线提问 .your classes begin at 7:33? We begin classes at 8：00（对begin classes提问） Classes begin at eight.对at eight提问 Classes begin at 8:00.为什么要用begin 下文说 Classes are over at four.为什么不可以说 Classes are begin at 8:00呢？ Our classes begin at eight in the morning.同义句 将begin at half classes past eight 连词成句 Classes begin at 8:30( 请翻译） Classes begin at 8:30(改为同义句） They begin classes at two o'clock and classes a_____ over four twenty-five.填什么 classes begin可不可以写成 begin the classes Our school ——at eight in the morning A.begin class B.begin classes C.begins classD.begins classes Our classes begin at 8:00.这里的 begin可以换成start吗? our classes begin at 8:00 a.m =____ ____ our classes at 8:00 a.m our classes begin at 8:00a.m.=_____ _____our classes at 8:00a.m.