重点讲解：
1. seem to do sth.
好像；似乎；看来；
eg. The days seem to flash by.
光阴似箭。
eg. The majority of people seem to prefer TV to radio.
多数人喜欢电视胜过广播。
2. switch off
关掉，关上（电灯等）；
eg. Be sure to switch off the light when you leave the room.
你离开房间时一定要把灯关掉。
eg. The conference soon starts, to ask position to switch off the handset.
会议即将开始, 请各位关掉手机。
3. keep out
防止进入；阻止；
eg. Not even the thickest jacket was enough to keep out the cold.
就连最厚的夹克也不足以御寒。
eg. We have screened our porch to keep out mosquitoes.
我们的阳台已装上了纱窗以遮蔽蚊虫。