今、TOEICの勉強をしています！
そこで、いまいち分からない問題があったので、質問させていただきました。

Our technicians insist that the problem will be fixed shortly. We will notify you when services ________ resumed.

a) are
b) had
c) have been
d) will have been


答がC)でした。　なぜ、完了形なのでしょうか。

記事番号：24199

重要度：★☆

Because you can't do one thing (notify) until another thing has been completed (resume services).

It's not "services have resumed" because services don't resume on their own. The technicians have to do that. So it's "services have been resumed."

Other examples:

"The house has been built" (builders built the house)
"The fugitive has been arrested" (the police caught him)
"The streets have been cleaned" (the cleaning crew cleaned it)

記事番号：24216

重要度：☆