起重滑车吊装时，动、定滑轮的最小距离不得小于滑轮轮径的()倍。
A.2
B.3
C.5
D.8
参考答案：C
The last letter ____ arrived yesterday morning left him______ very sad. [ ]
A. which; feel
B. which; to feel
C. that; feeling
D. /; felt
司机开车后，可以接听家里来的电话。
