位于前纵隔的肿瘤有()
A.胸腺瘤
B.皮样囊肿
C.畸胎瘤
D.神经纤维瘤
E.支气管囊肿
参考答案:A, B, C
用货车运水泥,要运45吨,已经运了15吨,剩下的用载重5吨的货车一次运完,需要几辆这样的货车?
-This bus is always late, __________?
-It sure is.[ ]
A. is not it
B. isn't it
C. isn't the bus
D. doesn't it