Standing on the top of the hill, one would not do anything, but _____ the flowing of the clouds around me.
| A．enjoy | B．enjoying | C．enjoyed | D．to enjoy |
-How amazing it is that astronauts are exploring outer space!
-It’s a challenge, I guess, _________man against nature.
| A．of | B．for | C．by | D．about |
When she first arrived in China, she wondered what the future might have_______ for her, but now all her worries are gone.
| A．in need | B．in time | C．in preparation | D．in store |
Are you ready for Spain?
Yes. 1 want the girls to experience that______they are young.
| A．while | B．until | C．if | D．before |
Scientists are convinced the positive effect of laughter physical and mental health.
| A．of; at | B．by; in | C．of; on | D．on; at |
If you really have to leave during the meeting, you’d better leave ____ the back door.
| A．for | B．by | C．across | D．out |