. As there is less and less coal and oil, scientists are exploring new ways of making use of ______ energy, such as sunlight, wind and water for power and fuel.
| A．primary | B．alternative | C．instant | D．Unique |
You can hardly imagine how excited I was when the day I had been looking forward to _____ at last.
| A．coming | B．come | C．came | D．comes |
The effect a teacher has _______ children may be greater than that of their parents.
| A．in | B．on | C．at | D．with |
—Everyone in my class passed the exam.
—Oh, really? It ________ difficult.
| A．can’t have been | B．needn’t have been |
| C．must be | D．mightn’t be |
I ran across David while walking along the street yesterday. I ________ him for three years.
| A．hadn’t seen | B．didn’t see |
| C．haven’t seen | D．don’t see |
—You are required by law _______ seat belts.
—Thanks for your reminding. I’ll do it right away.
| A．wearing | B．being worn | C．to wear | D．to be worn |