—I’ll take at least 2 hours to do this!

—Oh, _____!I could do it in 30 minutes.

A．come on

B．pardon me

C．you are right

D．don’t mention it

有些消化道肿瘤患者不能口服药物，可选用哪些镇痛方法（）

A.直肠给药

B.静脉PCA

C.硬膜外PCA

D.神经阻滞

E.针灸