We should protect the environment, for plenty of fresh air ________ to good health.
| A．adjust | B．contributes | C．distributes | D．attributes |
.I would be very glad to help, ___ I’m going away on business.
| A．and | B．or | C．for | D．only |
38.The task is hard, ___, the workers managed to finish it in time.
| A．therefore | B．otherwise | C．however | D．yet |
39.When you read the book, you’d better made a mark ____ you have any questions.
| A．at which | B．at where | C．place | D．where |
___ she will join us in the game is not decided yet.
| A．If | B．Whether | C．What | D．While |
There are many sports lovers in his office.Some love climbing, ___ others enjoy fishing.
| A．or | B．for | C．while | D．so |