重点讲解：
1. separate from (使)分离；
When the boosters have helped to lift a space station into orbit, they separate from it and return to the earth.
助推火箭把太空站推入轨道后，就自行脱落返回地球。
2. agree to do sth. 同意；应允；答应；
The club members did agree to modify their recruitment policy.
俱乐部成员的确同意修改吸纳新成员的政策。
3. be willing to do sth. 乐意的；愿意的；
While I am willing to help, I do not have much time available.
尽管我愿意帮忙，但是没有多少时间。
4. participate in 参加；参与；
She didn't participate in the discussion.
她没有参加讨论。