（Ⅰ）当m=6，n=100时，

（ⅰ）若数列A₆：11，78，x，y，97，90是一个“好数列”，试写出x，y的值，并判断数列：11，78，90，x，97，y是否是一个“好数列”？

（ⅱ）若数列A₆：11，78，a，b，c，d是“好数列”，且a＜b＜c＜d，求a，b，c，d共有多少种不同的取值？

（Ⅱ）若数列A_m是“好数列”，且m是偶数，证明： $\frac{a_1+a_2+\cdots +a_m}{m}\ge \frac{n+1}{2}$ ．

针对长江沿江地带东西部地形的客观差异，可采取的利用方式是（　　）

如图，在边长为a的正方形中剪去一个边长为b小正方形（a＞b），把剩下的部分拼成一个梯形，请利用甲、乙两图验证我们本学期学过的一个乘法公式．

词汇运用 用所给词的适当形式填空
⑴Thank you for____ on them on the plane. (operate)
⑵I thought of my good friend when I read your____ (advertise)
⑶We should help all children to get an____   at school. (educate)
⑷His father died because of____ (ill).
⑸The old man is ____  to the policeman. (grate)
⑹I was made____ (read) the text once more by Miss Chen.
⑺I think I should Share his ____ when he is sad. (happy)
⑻He says that he wants to be a____ (fly) doctor when he leaves school.
⑼I don't know what made him laugh so____ (excite)?
⑽My watch doesn't work. It needs to____  (repair).
⑾Coffee ____  by most Chinese people. (not drink)
⑿He spend his spare time____  watching TV. (most)
⒀The car was one of the ____ . (run)
⒁ORBIS is one of the____  in the world. (charity)
⒂Many people in poor area don't have enough money for____  treatment. (medicine)

在△ABC中，∠A=120°，∠B=45°，∠C=15°，则cosB等于（　　）