—Why didn't he attend the meeting yesterday?
—__________ he caught a bad cold and now he is in hospital.
| A．Now that |
| B．Since |
| C．Because |
| D．As |
She knows that as a secretary she must be pleasant and helpful no matter how busy she is or what kind of ____ she may be in.
| A．mood | B．mind | C．form | D．thought |
— ____ sweep the classroom yesterday？
—I was playing tennis with my friend．
| A．Why not | B．Why didn't | C．Why don't | D．Why didn't you |
He didn’t _____ to the news.
| A．answer | B．reply | C．react | D．hear |
In the Great Depression, the American government couldn’t find good solutions _____ the unemployment problem.
| A．of | B．to | C．on | D．about |
In January, 2004, the United States successfully launched “Spirit”, a Mars Exploration Rover, _____ a new milestone in the history of mankind.
| A．it marked | B．marking | C．marked | D．to mark |