呃,什么是关系代词啊?不应该是可以使用吗,为啥叫省略呢
1.I can't read the letter which Billy wrote last week.
2.Can you lend me the CD that you bought yesterday.
3.The person who I met in Paris knows you.
4.The knife my mother bought last week is very sharp.
5.The baby which you can see is only a few months old.