__________ the class, the students left the classroom one by one.
A. At the end of B. In the end C. By the end
This book cost her twenty yuan , ?
| A．didn’t it | B．doesn’t it | C．did it | D．does it |
Help others whenever you can you’ll make the world a nicer place to live.
| A．and | B．but | C．or | D．unless |
—I know nothing about the history of the telephone. Could you tell me ?
— Yes, in 1876
| A．who invented the telephone |
| B．how the telephone was invented |
| C．when was the telephone invented |
| D．when the telephone was invented |
The sick in our country taken good care of by the government.
| A．is | B．are | C．has | D．have |
—Would you like camping with me?
— I’d like to. But I’m busy my homework.
| A．to go; to do | B．to go; doing | C．going; to do | D．going; going |