We can relax ourselves by taking part in school activities after long hours’ study; _______, we
can learn a great deal from other students.
| A．therefore | B．but | C．however | D．besides |
The air is deadly polluted because some factories don't ________ the rules to protect the environment.
| A．appreciate | B．regard |
| C．honor | D．respect |
The visiting minister expressed his satisfaction with the talks, ______ that he had enjoyed his stay here.
| A．having added | B．to add |
| C．adding | D．added |
You should try not to get ________ in the trouble between them.
| A．lost | B．involved |
| C．absorbed | D．trapped |
Many countries are in great need of natural gas, wind and other forms of ________.
| A．power | B．source | C．energy | D．material |
Good heavens! There you are! We were all ________ about your safety. We were expecting you to come back much earlier all through the night.
| A．curious | B．concerned |
| C．upset | D．interested |