1.letter of application 申请函、求职申请书
例句：We have received over 2000 letters of application for the job.
我们已经收到2000多封申请该职位的来信。

2.letter of rejection 回绝函
例句：About one month after he sent the application, he got a letter of rejection.
寄出申请的一个月后，他收到一封回绝函。

3.letter opening machine 拆信器
例句：A letter opening machine cuts open envelopes of letters received.
用拆信器来拆开收到的信件。

4.letter of intent 意向书（表明诚意要做某事的正式文件，但不属于承诺或合同）

5.letter quality printer 优质字符打印机（能打印出清晰字体，适合商务通信）
例句：Make sure you use the letter quality printer to print out those letters.
请务必使用优质字符打印机打印这些信件。