13. How did you sign the letter?
你在信上是怎样署名的?
还能这样说：
What did you add your signature to the letter?
How did you put your name in the letter?
应用解析：
take sth. in the letter 从字面意义上理解某事;
to the letter 严格按照字句
14. Do you know how to write an English letter?
你知道怎样用英语写信吗?
还能这样说：
Can you tell me how to write in English?
Could you let me know how to write in English?
应用解析：
nothing to write home about 不值得大书特书的事情;平平常常;
write over 改写，重写
15. Don't forget to drop me a line.
别忘了给我写信。
还能这样说：
Remember to write to me.
Don't forget to write me a letter.
谚语：
One must draw the line somewhere.
人之所为，总有限度。
16. I'm writing to tell you that I was admitted by Harvard University.
我写信告诉你我被哈佛大学录取了。
还能这样说：
I'm writing to you that I have got the admission letter of Harvard University.
I am telling you that I have passed the exam of Harvard University.
17. The girl wrote the letter with a pencil.
那个女孩用铅笔写信。
还能这样说：
The girl used a pencil to write the letter.
The girl wrote the letter in pencil.
谚语：
Wine and judgement mature with age.
酒老味醇，人老识深。