①____；

②____．

比40米多 $\frac{1}{4}$ 的是（  ）

根据句意及汉语提示，写出各单词的正确形式。
⑴We'll have to____ （训练）before the next match.
⑵Our teachers often ____  (鼓励)students to ask questions in class.
⑶The girl ____  (尖叫) when she saw the snake.
⑷The old man is very sick. He takes a lot of ____  (药) every day.
⑸____  (令人伤心地), many people still don’t want to take any actions to protect the animals.
⑹It is really ____ (幸运的) for me to pass the driving exam .
⑺ Millie didn't clean the room last week, she visited her friends____  (代替).

（Ⅰ）求椭圆C的方程；

（Ⅱ）直线l分别切椭圆C与圆M：x²+y²=R²（其中3＜R＜5）于A、B两点，求|AB|的最大值．