---What do you think of teaching , Bob？
---I find it fun and challenging. It is a job ___you are doing something serious but interesting
| A．where | B．which | C．when | D．that |
The students entered the classroom, smiling and _______, and _____ down to have their lessons.
| A．talked , sat | B．talking, sitting | C．talking , sat | D．talked; sitting |
If your knowledge can be in some way ______ with my experience， we are sure to succeed.
| A．joined | B．connected | C．united | D．combined |
If you put too many oranges in that paper-bag it will _____.
| A．spread | B．explode | C．crash | D．burst |
The physics teacher told the students to observe carefully what would happen when a (n) _____ acted on the object.
| A．force | B．energy | C．power | D．strength |
Practising Chinese kung fu can not only _____ one’s strength, but also develop one’s character.
| A．bring up | B．take up | C．build up | D．pull up |