Does your class .... forty students? Mai is waiting ... us at school

Fill in the blank 
Câu 1: Does your class .... forty students ? 
Câu 2 :  ... Nam buy any clothes in the shop yesterday ? 
Câu 3 : Mai is waiting ... us at school . 
Câu 4 : ... many hours a day do your babies sleep ? 
Câu 5 : ..... book is that ? It's Mai