____ on ten years of observation and study, the story shows that everyone dreams every night, whether they realize it or not.
| A．Basing | B．Based |
| C．Being based | D．Having based |
Jack is a great talker. It's high time that he ________ something instead of just talking.
| A．will do | B．has done |
| C．do | D．did |
It is necessary that the government solutions for the problems of air pollution to create a clear environment.
| A．should have found | B．could have found |
| C．could find | D．should find |
We lost our way in that small village, otherwise we________ more places of interest yesterday.
| A．visited | B．had visited |
| C．would visit | D．would have visited |
If we _______ adequate preparations, the conference wouldn’t have been so successful.
| A．haven’t made | B．wouldn’t make |
| C．didn’t make | D．hadn’t made |
Without the development of the Internet, Taobao and Tmall______$ 5.7 billion in sales on 11 November, 2013.
| A．wouldn't make | B．didn't make |
| C．hadn't made | D．wouldn't have made |