Do you know ______ this i-pad belongs to? – Let me see. Oh, it’s ______.

The students found it easy to_______ what the experienced teacher had taught.

David, how old is your father this year? – ———— And we just had a special party for his _____ birthday last weekend.

The workers recycle the old newspapers ______use them．

What’s _______name?—Betty. She is my friend.