Scientist are not sure about the ___________ of water on the Mars.
| A．occupation | B．existence | C．demand | D．treasure |
________a reply from my American friend Bill, I decided to send another email to him.
| A．Not having received | B．Not being received |
| C．Not receiving | D．Not to receive. |
As the clock struck nine, players ______their positions and the match began.
| A．stood up | B．took up | C．made up | D．set up |
There ______ quantities of apples in the basket and there was ______ milk in the bucket.
| A．were; a number of | B．was; quantities of |
| C．were; a quantity of | D．was; a good many |
You were rude to your sister, _____you should make an apology to her.
| A．whom | B．for which | C．for whom | D．which |
Something unexpected happened, but _______ it was a pleasant journey.
A．in detail |
B．on average | C．to a degree | D．on the whole |