證明信：行業(yè)成績(jī)證明書(shū)等等，是用來(lái)證明一個(gè)人的身份、學(xué)歷、婚姻狀況、身體情況等或某一件事情的真實(shí)情況。證明信的寫(xiě)法通常也采用一般信件格式，但多省掉收信人的 姓名、地址和結(jié)束用語(yǔ)。稱呼多用“To Whom It May Concern”意即“有關(guān)負(fù)責(zé)人”，但此項(xiàng)也可省略。寫(xiě)證明書(shū)要求言簡(jiǎn)意賅。

　　Doctor’s Certificate

　　June. 18, 2000

To Whom it may concern,

　　This is to certify that the patient, Mr. Tomas, male, aged 41, was admitted into our hospital on June. 9, 2000, for suffering from acute appendicitis. After immediate operation and ten days of treatment, he has got complete recovery and will be discharged on June. 19, 2000. It is suggested that he rest for one week at home before resuming his work.

　　Jack Hopkins

　　Surgeon-in-charge