重点讲解：
1. in the middle of 中部；中央；中间；
例句：He is standingin the middle ofthe classroom.
他正站在教室中间。
2. as well 也；还；
例句：She is not only good at mathematics, but she is interested in Englishas well.
她不但擅长数学，而且对英语也感兴趣。
3. of course （表示通常、显见或众所周知的事实）当然，自然；
例句：That was 40 years ago, butof courseyou wouldn't remember it.
那是40年以前的事，你自然想不起来了。
4. stick to 坚持不变；
例句：She did everything by fits and starts, butstuck tonothing long.
她做事总是凭一时高兴，什么事都干不长。
