1. The curtain hooks run along a slot in the curtain rail.
   窗帘的吊钩可沿轨槽滑动.
2. He leant on the railing.
   他斜倚栏杆。
3. I'm afraid the engine will run off the rails.
   我怕火车头要出轨了。
4. I have forwarded you by rail the books you wrote for.
   我已经把你写信来索取的书由火车递寄给你。
5. He pitched over the railing.
   他摔出栏杆外

　2个名词解释