—Kitty, will you go to see Spider-Man 3 with us this evening?

—Sorry. I ______ the film already. [ ]

A. saw

B. have seen

C. had seen

患者男，60岁，因“活动后憋气3周”来诊。查体：头部肿胀，颈部可见颈静脉怒张。胸部CT：前纵隔巨大肿物，8cm×6cm，外形不规则，包绕两侧无名静脉，其他组织器官未受侵犯。增强CT：肿物不均匀增强，局部有坏死。

如术后需要加辅助放射治疗，临床常用的剂量是（）.

A.40～70Gy

B.40～60Gy

C.50～80Gy

D.50～90Gy

E.30～50Gy

F.30～70Gy