在最末一次罚球中，球碰篮圈并向上弹起，又停留在篮圈上，这时不能触及球。
参考答案：对
_ Who's that boy reading in the garden? Is it David?
_ It __________ be David. I saw him in the classroom just now.[ ]
A. must
B. can't
C. may
D. shouldn't
停机时，为什么要进行盘车？
