重点讲解：
1. pull the plug on sth.
停止；中断；取消；
eg. The banks have the power to pull the plug on the project.
银行能让该工程下马。
eg. Finally the president to pull the plug on selling this medicine.
最后，总裁决定停止销售这种药品。
2. switch off
关掉，关上（电灯等）；
eg. Please switch off all mobile phones, since they can interfere with the aircraft's navigation systems.
请您关掉手机，因为它会影响飞机的导航系统。
eg. In case of operation failure, please switch off the power.
如发现异常或操作有任何问题，请务必先切断电源。
3. do sb. a favor
恩惠；帮忙；
eg. I request you to do me a favor.
请你帮我一个忙。
eg. Could you do me a favor? My computer suffered from computer virus.
能帮帮我吗？我电脑中病毒了。
4. light up
现出吃惊的神情；露出喜色；
eg. You should see his eyes light up when he talks about home.
你真该看看他谈到家的时候眼睛放光的模样。
eg. She was relieved to see his face light up with a boyish grin.
看到他脸上现出孩子气的笑容，她总算松了口气。
