谓语中的被动语态,主句的主语被怎样:be + done
will/should/would……be done 将来时态
be going to be done 打算将来被动
is/am/are done 一般被动
were/was done 过去时态
have/has been done 完成时态
had been done 过去完成时态
has/have been being done 完成进行被动
非谓语中被动
to be done
being done
to have been done
having been done
这题考察非谓语中 v-ing的被动
appreciate 后+v-ing
又是被邀请
所以appreciate being invited