重點講解：
1. come upon
偶然碰到（或發現）；
eg. I came upon an irresistible item at a yard sale.
在一次庭院拍賣會上，我偶然發現了一個忍不住想買的東西。
eg. I come upon a group of children play in the street.
我遇到一群孩子在街上玩耍。
2. figure out
想出；理解；弄清；
eg. I can't figure out what he was hinting at.
我想不出他在暗示什么。
eg. It took her a long time to figure out who the wrongdoer was.
她用了很長時間才琢磨出誰是做壞事的人。
3. be able to do sth.
能做到某事；
eg. Women seem to be able to multitask better than men.
女性似乎比男性更擅長同時做數件事情。
eg. At last they were able to feel secure about the future.
他們終于覺得不必為將來而擔憂了。
4. chop down
砍倒；伐倒；
eg. Sometimes they have to chop down a tree for firewood.
他們有時只好砍樹當柴燒。
eg. Every morning the old man went out to chop down trees.
每天一早，老人就去森林伐木。
5. work out
（如期）發生；進展（順利）；
eg. I hope it will work out well.
我希望進展順利。
eg. The deal just isn't working out the way we were promised.
結果待遇根本不是他們對我們許諾的那樣。
6. turn into
（使）變成；（使）成為；
eg. A prince turns into a frog in this cartoon fairytale.
在這個卡通童話里王子變成了一只青蛙。
eg. He decided to turn his hobby into a lucrative sideline.
他決定把自己的愛好變成賺錢的副業。