Smoking, which may be ________ fun for some people, is ________ cause of discomfort for the people around him.

A．/; a

B．a; a

C．a; /

D．a; the

大剂量静脉给药可引起呼吸抑制的是（）

A.紫杉醇

B.平阳霉素

C.三尖杉酯

D.甲氨蝶呤

E.奥沙利铂