水准测量中丝读数前（）符合水准气泡两端影像精密符合。
A.需要
B.不需要
C.随意
D.粗略整平
参考答案：A
His ambition is _______ volleyball in the Olympics.[ ]
A. play
B. to play
C. played
D. plays
-Write to me when you get home. -OK, I（）
A.must
B.should
C.will
D.can
