His MP5 is very useful, _______?[ ]
A. isn't it
B. is it
C. does it
D. doesn't it
答案:A
肝癌患者行介入栓塞化疗术最常用栓塞剂是()
A.NBCA胶
B.38%碘化油
C.40%碘苯酯
D.60%泛影葡胺
E.40%Gd-DTPA
动物蜡