His waltzes _____ him famous all over Europe.[ ]
A. kept
B. made
C. felt
答案:B
下列何药对肉瘤疗效好:
A.丝裂霉素B.博来霉素C.环磷酰胺D.甲氨蝶呤E.卡莫司汀
电路中有电流的条件一是电路中必须有______,二是电路形成______;我们规定______电荷移动的方向为电流方向(选填“正”、“负”).