将下列句子合成一句（宾语从句）快!
问题描述：
将下列句子合成一句（宾语从句）快!
1)The letter was from my parents .I received the letter .
2)This is the doctor .The doctor saved they boy's life.
3)Do you know the music .I can dance to the music.
4)Do you know the young lady?my mother is talking with the lady.
答
是合成定语从句吧1)I received the letter which was from my parents .2)This is the doctor .who saved they boy's life.3)Do you know the music which I can dance to?4)Do you know the young lady whom / who ...