Sensible people don’t think it is_______ to buy things which are not needed even at a low price.
| A．worth | B．worthy | C．worthless | D．worthwhile |
No one has yet succeeded in solving the _____ of how life first began.
| A．biology | B．gravity | C．puzzle | D．theory |
Can you tell me ______?
| A．what does the island look like | B．what the island looks like |
| C．how does the island look like | D．how the island looks like |
—She looks very happy. She ______ have passed the exam.
--I guess so. It’s not difficult after all.
| A．should | B．could | C．must | D．might |
Mary,along with her parents,______to Paris.
| A．have moved | B．has moved | C．are moving | D．have been moving |
The students were studying in classroom when, all of sudden,the lights went out.
| A．不填;不填 | B．a;the | C．the;a | D．the；不填 |