I commanded that he at once.
| A．left | B．leaves | C．leave | D．to leave |
_______by the beauty of the piano music, the audience almost forgot to applaud when the pianist finally finished it.
| A．Having attracted | B．Attracted | C．To be attracted | D．Be attracted |
John’s ability to learn from observations and experience_______ greatly to his success in public life.
| A．owed | B．attached | C．related | D．contributed |
--- Is there any possible way to help them get rid of such a bad habit?
--- To tell the truth, it’s very hard. But we teachers _______on this problem.
| A．are working | B．had worked | C．worked | D．had been working |
--- Why were you absent yesterday?
--- I caught a cold, _______I had been walking around in the rain.
| A．but | B．so | C．and | D．for |
A subway is an effective way to solve traffic problems in_________big city. It has evident advantages, such as_______speed and convenience.
| A．the; the | B．a; the | C．a; / | D．the; a |