We can never expect____bluer sky unless we create____ less polluted world.
| A．a; a | B．a; the |
| C．the; a | D．the; the |
If better use is __________ of your spare time, you'll make great progress in your study.
| A．spent | B．taken |
| C．given | D．made |
English is difficult __________ well in a short time.
| A．to learn | B．learning |
| C．to be learned | D．learn |
Paul doesn't have to be made __________. He always works hard.
| A．learn | B．to learn |
| C．learned | D．learning |
The careless driver is __________ for the traffic accident that __________ yesterday.
| A．to blame; happened | B．to blame; was happened |
| C．to be blamed; was happened | D．to be blamed; happened |
It is often __________ that human beings are naturally equipped to speak.
| A．said | B．to say |
| C．saying | D．being said |