–Look! The man at the gate ____ be our headmaster. He is always standing there every morning.
-- No, it _____ be him. He is holding a meeting in the office now.
| A．must; can’t | B．must; mustn’t |
| C．can’t; can’t | D．can’t; mustnit |
. —Did you get there by ______ bike?
—No, I took ______ taxi.
| A．a; a | B．不填; a | C．the; the | D．a; the |
Why don’t you ________？
A．write down it B．write down C．write it down
I ________ the living room．Look，it is clean．
A．clean B．am cleaning C．have cleaned
The children ________ at the table when their mother cooked in the kitchen．
A．wait B．are waiting C．were waiting
--How many times has Chang’eⅠ ________ the Moon？
--Only once．It went there last year．
A．go to B．gone to C．been to