If we go on using energy so wastefully, __________ are that our oil wells will be dried up before new energy sources can be found to replace oil.
| A．chances | B．opportunities | C．questions | D．problems |
________our manager objects to Tom's joining the club，we shall accept him as a member.
| A．Until | B．Unless | C．If | D．After |
We________on this project for four hours.Let's have a rest.
| A．are working | B．have been working |
| C．worked | D．had worked |
Tom________tell the truth to his boss because he didn't want to make trouble.
| A．daren't to | B．dare to | C．dared not | D．dare |
Our boss is very ________，so we have to arrive on time，or we would be fined.
| A．serious | B．strict | C．energetic | D．organized |
Mark was afraid of being scolded，so he________say what he thought to his parents.
| A．dare not to | B．doesn't dare to |
| C．dared not to | D．didn't dare to |