You will find the game is not so difficult to play ______ you understand its rules.
| A．until | B．since | C．before | D．once |
They will start their project ____at helping the poor children to be educated in China＇s west.
| A．aims | B．aiming | C．being aimed | D．aimed |
Could it be in the restaurant in ___ you had dinner with me yesterday ___ you lost your handbag.
| A．that; which | B．which; that |
| C．where; that | D．that; where |
By now, when one makes a large purchase, he should have ___ opportunity to change his mind.
| A．accurate | B．urgent | C．special | D．adequate |
It is a long time ___
| A．when I saw you last | B．since l saw you last |
| C．for I saw you last | D．then I saw you last |
Sam _______some knowledge of the computer just by watching others working on it.
| A．brought up | B．looked up | C．picked up | D．set up |