男性，28岁，近8年反复咯血多次，小至中等量，无咳嗽、咳痰，肺部体征阴性。

诊断首先考虑（）。

A.支气管扩张

B.肺结核

C.支气管肺癌

D.支气管内膜结核

E.慢性支气管炎

—Dad, why should I stop              computer games?

—For your health, my boy, I'm afraid you              . [ ]

A. to play ; must

B. playing ; have to

C. to play ; can

D. playing ; may