---Come on boys! The bell is ringing it’s time class.-OK. Let’s. A. have to go B. to

问题补充：

---Come on, boys! The bell is ringing, it’s time class.

---OK. Let’s.

A. have, to go B. to have, go C. having, go

答案：

解析：本题考查的是its time to do sth，而后一空let sb do sth，表示让某人做某事，故选B