Visitors to the National Museum can avoid long lines at the ticket booths by purchasing tickets ____.
| A．in advance | B．in detail | C．out of order | D．with caution |
---I wonder why Mr Green hasn’t showed up at the meeting yet.
---I’m not sure, but he _______ in a traffic jam driving here.
| A．could be stuck | B．might stuck |
| C．might have been stuck | D．must have stuck |
When I got to the cinema, the film _____ for five minutes.
| A．had begun | B．has been on |
| C．has begun | D．had been on |
Mary had promised to give me a ticket for tomorrow. She failed, ____.
| A．either | B．though | C．but | D．too |
—He must be busy doing his homework right now.
—I imagine____.
| A．that | B．to | C．so | D．it |
Lu Xun was ___________ medical student before he turned ___________ great writer.
| A．the; the | B．the; a | C．a; / | D．a; a |