对乳腺癌有效的药物（）
A.5-FU
B.MTX
C.塞替派
D.糖皮质激素
E.丝裂霉素C
参考答案：A, B, C, E
---He seems to be a teacher.
---______. He has been a teacher for 20 years.
A．So he does
B．So he is
C．So does he
D．So is he
用风动砂轮修磨刃口时，要求速度慢、压力轻，是为了避免（）
A.刃口修磨过头
B.刃口部位发生裂纹
C.刃口部位发生退火
D.刃口与砂轮撞磕
