The dominant language of e-mail is English. A traditional English letter usual
ly begins with an address, the date and perhaps the address of the addressee.
_____ the email system itself inserts theses things, is there any point in put
ting them in?
选项有What if But if As if Not if
我选What if 但答案是But if
Not if翻译是如果...则不
他跟if not 有什么差别吗