It is hard to say what kind of person he is．Sometimes he is very friendly; at other times he ___ be very cold．

What do you think of the play —–Terrible! I have neverseen________one

I’m sure you will do better in the test because you ______ so hard this year

I like this English song and it ___________ many times on the radio.

I met a few friends of mine, one of ____ is a singer.