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

Who taught ________ to write the computer programs? —Nobody. She learned it by __________.

Please pay attention _____ what your teacher says in class. [ ]

good manners to say “Sorry” when you knock into someone butno need to say it again and again .

Where is your father? —He _______ to Shanghai. He has ever ______ there twice.