Question

_________ automatically, the e-mail will be received by all the club members．

1. A.
   Mailed out
2. B.
   Mailing out
3. C.
   To be mailed out
4. D.
   To mail out

Answer 1

A
由下文知，the e-mail与mail out之间是逻辑上的动宾关系，故用过去分词。