After visiting Harbin, most of the foreign friends said they would never forget the time ________ they had spent.
| A．that | B．what |
| C．when | D．at which |
Some of this heat near the earth’s surface _________ make electricity.
| A．is used for | B．is used to | C．gets used to | D．used to |
The cunning fox tricked the little rabbit _________ picking up the carrots in the field and then caught it.
| A．on | B．into | C．along | D．to |
You must keep ____ in mind _____ your are a student in this school and should obey the school rules.
| A．it ; that | B．everything ; which | C．such ; as | D．something; because |
A cook will be immediately fired if he is found _____ in the kitchen.
| A．smoke | B．smoking | C．to smoke | D．smoked |
The traveler couldn’t make himself _____ in his poor English.
| A．understand | B．understanding | C．to understand | D．understood |