It was only after he had read the papers _______ MrGross realized the task before him was extremely difficult to complete

At this moment the bell rang _______ theend of class

We ________ a sign at the park entrance to tell people to protect the trees and flowers.

nted sheep, I drank milk and I tried everything,but nothing helped. —It seems you _____ too much recently.Try some sleeping pills.

Can you tell me __________________—Sorry, I can hardly understand its meaning.