根据代销业务的规定，代销产品或行为涉及两个及以上一级分支机构的，应由总行与被代理机构总部统一签订协议接受委托。

Electronic mail, or mail, as it is known to its many fans, has been around for over two decades. Typically, email systems support five basic functions, as described below. (41) refers to the process of creating messages and answers. (42) refers to moving messages from the originator to the recipient. (43) has to do with telling the originator what happened to the message. Was it rejected Was it lost (44) incoming message is needed. So people can read their email. (45) is the final step and concerns what the recipient does with the message after receiving it.

（43）是（）

A.Composition

B.Transfer

C.Reporting

D.Displaying