Letters do not repeat
字母───letter;不───no
letter was returned unopened.───信被原封不动地退回了。
Your letter was very welcome.───很高兴收到你的信。
letter was intercepted.───信被截查了。
With the eyes of the many girls and boys looking at my back I froze inside and I was unable to write a single letter.───在身后那么多男女同学的众目睽睽之下，我心里象结冰一样，一个字母也写不出来。
will provide with a commentary of the book block, a procedure known as a coat book by the cover letter process, also known as mis-viewing.───将订联成册的书芯，包上外衣封面的过程称书封加工，也称装帧加工。
If I said, I dissolved the love letter in the early morning first crystal clear dewdrop, you could say romantically?───如果我说，我把情书溶进了清晨第一颗晶莹的露珠里，你会不会说浪漫？
We are sorry for not answering your letter sooner.
His letter was completely without punctuation.
A smart coat is a good letter of introduction.
The letter is ready for the post.
You should apply in person / by letter.