If your knowledge can be in some way _______ with my experiences, we are sure to succeed.
| A．joined | B．united |
| C．connected | D．combined |
She had to leave school_______ her family couldn’t afford her education.
| A．although | B．unless |
| C．because | D．so |
The old man has retired from the factory. He _____ there for 30 years.
| A．works | B．worked |
| C．has worked | D．was working |
— I don’t mind telling you what I know.
— You _______. I can manage it myself.
| A．mustn’t | B．ought not to |
| C．can’t | D．don’t have to |
The boys enjoy playing basketball __________ many of the girls relax by playing ping-pong.
| A．while | B．or | C．since | D．if |
The teacher asked the students to do the experiment __________ small groups.
| A．to | B．for | C．on | D．in |