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 |
In the city, I saw so grand a National Day celebration _______ I never dreamed of．
| A．which | B．as | C．that | D．when |
If only I _______ more confidence in the English speech contest held last week!
| A．would have | B．had | C．had had | D．have |
According to the school rules, no child _______ be allowed out of the school during the day, unless accompanied by an adult．
| A．will | B．would | C．might | D．shall |
It was not until 1911, _______ the first vitamin was identified, _______ people realized the importance of it．
| A．when; which | B．when; that | C．that; which | D．that; that |
The moment I completed the 800-meter race in the school sports meet, my legs _______．
| A．gave out | B．gave away | C．gave in | D．gave up |