The running water makes the stones ______ very smooth.
| A．sound | B．taste | C．smell | D．feel |
If you stay here longer, you may. But you leave before this weekend.
| A．will; must | B．can; can |
| C．may; will | D．may; shall |
All flights owing to the heavy fog, many passengers could do nothing but take trains.
| A．to be cancelled |
| B．were cancelled |
| C．have been cancelled |
| D．having been cancelled |
More than one worker sent to the training center to improve their working skills in the past three years.
| A．is | B．has been |
| C．are | D．have been |
We can never forget the days we worked together and the days we spent together.
| A．when; which | B．which; when |
| C．what; that | D．on which; when |
South Korean rapper PSY’s hit song Gangnam Style made history on December 20 as first-ever video on youtube. com to reach 1 billion views.
| A．the; the | B．/; the |
| C．a; a | D．/; a |