Look! Those boys are a bus.A. waiting forB. waitC. wait forD. waiting

问题补充：

Look! Those boys are a bus.

A. waiting for

B. wait

C. wait for

D. waiting

答案：

(答案→)A. waiting for

B. wait

C. wait for

D. waiting

解析：“看看！那些男孩在等公共汽车。”既然能看到，说明他们现在在等，故用现在进行时，选A。wait for是固定搭配“等待”。