on the portrait, mother was deep in thought.
—Thank God we’ve finally cleared up some problems. Let’s ______, shall we?——All right. See you tomorrow.
So far all cloned animals have suffered from some different serious disorders, ______ dying soon after birth.
—The room is in a mess again! ——Sorry. It is ______ who ______.
——Why didn’t you call me this morning?——I ______ call you. I called you all the morning, but I couldn’t ______.
When ______ by the teachers, a student tends to study harder than usual.