重点讲解：
1. used to do sth. 过去常常；过去曾；
I used to live in London.
我曾经在伦敦居住过。
2. pay for 付；支付；
I'm in a bit of jam, I haven't got enough money to pay for this meal.
我碰到了一点麻烦，我没有足够的钱来付这餐饭。
3. compared with 与…相比；和…比起来；
Overall industrial production was up compared with last year.
与去年相比，整个工业产值上升了很多。
4. turn into (使)变成；(使)成为；
A prince turns into a frog in this cartoon fairytale.
在这个卡通童话里王子变成了一只青蛙。