等底等高的两个平行四边形，一定也能拼成一个大平行四边形。[ ]
错误
黏度的表示方法有哪3种？各种黏度的概念是什么？
—Shall I inform him of the change of the schedule right now?
—I am afraid you _______,in case he comes late for the meeting.
A．will
B．must
C．may
D．can
