会计师事务所应当周期性地选取已完成的业务进行检查，周期最长不得超过()年。在每个周期内，应对每个项目负责人的业务至少选取()项进行检查。

A.3;2

B.2;3

C.1;1

D.3;1

—Look, an old man is in the middle of the road. It’s too dangerous.

—Let’s go and help him go __________the road.

A．over

B．on

C．across

D．through