24. Only when the meeting began _______ that he had left his papers at his office.
| A．will he realize | B．he did realize | C．did he realize | D．should he realize |
I didn’t know the girl youthe sheep.
| A．had fed | B．had her fed | C．had feed | D．had to feed |
_______ the tower building，where you can see the whole city．
| A．Standing on the top of | B．If you climb to |
| C．When you reach the top of | D．Get to the top of |
Why did they keep trying _________ they must have known it was hopeless?
| A．if | B．because | C．when | D．whether |
Having got up late this morning, Mike ran as fast as he could _______ to catch the bus.
| A．hope | B．to hope | C．hoped | D．hoping |
Their products enjoy 30 percent_____ of the market in this country because both the quality and their service are fine.
| A．share | B．profit | C．possession | D．advantage |