—Why are the lights in the teachers’ office still on?
—There ________ be some teachers working there.
| A．can | B．must | C．may | D．ought to |
—He plays basketball so well! Who taught _______?
—He learnt it by _______.
A. him; him B. him; himself C. himself; him
—Must I take part in the activity?
—No, you _______. You’re too young. You should look after yourself.
A. mustn’t B. can’t C. don’t have to
Running every day ______ good for my health.
A. is B. areC. am
Last month, I _______ the high jump in our school sports meet.
A. took part in B. joinedC. join
Sam spends two hours _______ his homework every day.
A. to do B. doing C. do