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 |
______ for two days, Steve managed to finish his report on schedule.
| A．To work | B．Worked |
| C．To be working | D．Having worked |
I ______ have worried before I came to the new school, for my classmates here are very friendly to me.
| A．mightn’t | B．mustn’t |
| C．needn’t | D．couldn’t |
Jane can’t attend the meeting at 3 o’clock this afternoon because she ______ a class at that time.
| A．will teach | B．would teach |
| C．has taught | D．will be teaching |
______in painting, John didn’t notice evening approaching.
| A．To absorb | B．To be absorbed |
| C．Absorbed | D．Absorbing |
-Jack, you seem excited.
-? I won the first prize in the English speech contest.
| A． | Guess what | B． | So what |
| C． | Pardon me | D． | Who cares |