提出大陆漂移假说的德国科学家是[ ]
A.麦哲伦
B.哥白尼
C.魏格纳
D.哥伦布
答案:C
— John, my computer doesn't work.
— Why not ask Mr Liu _____ it? [ ]
A. to buy
B. not to buy
C. to check
D. not to check
生产经营管理费用