参加献血后，血液最多（）可恢复到原来的水平。
A.半年时间
B.3-4个星期
C.一年时间
D.5-6个星期
参考答案：B
—Did you see Mr Smith when you were in France?
—No. When I _______ France, he _______ to China.[ ]
A. had arrived in; had gone
B. arrived in; has been
C. got to; had gone
D. had got to; had been
进入21世纪，中国大米加工业技术装备的水平得到了极大的提升，自主设计制造的什么设备已达到国际先进水平？
