阻止嘧啶类核苷酸形成的药物是()
A．环磷酰胺
B．顺铂
C．氟尿嘧啶
D．巯嘌呤
E．甲氨蝶呤
参考答案：C
—Did you have a good weekend?
—________. I was busy studying for the test. [ ]
A. Sure
B. I think so
C. I am afraid not
D. I hope not
第29届奥运会在中国北京成功举行，吸引了许多国内外的游客．这一年的二月份有29天．______．
