Peter, how old is your father this year?— _____. And we just had a party to celebrate his ______ birthday last weekend.

The math problem is too difficult ,I can’t__________ .

Is it the first time you _______ Beijing?—-No. But the first time I ______ here, the city wasn’t so beautiful.

Though I ______ the telephone number many times, the foreigner couldn’t write it down.

Peter, did you hear any noise?－Sorry, I ________ newspapers.