______ their return, they were praised as national heroes.
| A．At | B．By | C．On | D．With |
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 |
We’ve just heard a warning on the radio _______ a typhoon may be on its way．
| A．what | B．when | C．which | D．that |