This morning Jack came to school _________ than _________ student in his class.

A．much late; any

B．much late; any other

C．much later; any

D．much later; any other

射钉枪在使用结束时或（）之前，不准装射钉弹。

A.使用开始

B.更换零件

C.使用间隙

D.断开射钉枪