重点讲解：
1. hunt for
搜寻；寻找；
eg. Bats sleep in the daytime and come out to hunt for food at night.
蝙蝠白天睡觉，而夜间出来觅食。
eg. He turned the room upside-down to hunt for the lost key.
他把屋子翻得乱七八糟，寻找遗失的钥匙。
2. be set to do sth.
做好准备的；可能做某事；
eg. He is set to pulverise his two opponents in the race for the presidency.
他决心在总统竞选中彻底击垮他的两个对手。
eg. All my bags are checked in. I guess I'm all set to go.
我的行李都检查完了，看来我可以走了。
3. step in
介入，干预，插手（棘手问题）；
eg. There are circumstances in which the State must step in to protect children.
有些情况下，国家必须出面保护儿童。
eg. If they step in where they're not wanted, they'll get their noses put out of joint.
如果他们介入与他们无关的事，会有人阻止他们的。