---Sam becomes the top student because he is very clever.

---_______. Without the help of his hardworking teachers, he can’t make it at all.

A．I don’t think so.

B．I’m afraid so.

C．I agree with you.

D．I don’t know.

女性，23岁。干咳、低热、咯血，该患者首先应做哪项检查（）

A.胸部CT

B.纤维支气管镜检查

C.血气分析

D.肺功能

E.胸部X线检查