将8个不同的小球全部放入编号分别为1、2、 3的三个盒子里,使得放入每个盒子里的球的个数不少于该盒子的编号,则不同的放球方法共有________种(用数字作答).
2268.
用所给单词的适当形式填空。
1. Why does Charlie think _____ (borrow) magazines might be a good idea?
2. How about _____ (listen) to the radio in English?
3. There are many _____ (different) between the two factories.
4. Why did you want _____ (invite) your friend to your club?
5. Can you tell me how I can practice _____ (speak) English?
一个完全竞争厂商在短期均衡时可能是()。
A.AVC下降
B.AC下降
C.MC下降
D.一可变要素的平均产量上升