阿霉素（）。
A.烷化剂
B.抗代谢药
C.抗肿瘤抗生素
D.抗肿瘤植物药
E.抗肿瘤激素
参考答案：C
（王国维的）“境界”说
—I was told to be here before eight.
—Oh, you _______. I'm sorry for not telling you we have changed the plan. [ ]
A. must
B. can't
C. may
D. needn't
