关于口袋的形态，哪种口袋的形态变化最丰富，装饰最多（）。
A.贴袋
B.挖袋
C.插袋
D.三种均可
参考答案：D
命题：“若x2=1，则x=1，或x=-1”的逆命题是______．
Someone ____ my umbrella! It is all wet. And it was wet yesterday and the day before yesterday. [ ]
A. has used
B. has been using
C. used
D. is using
