______ medicine works in a human body is a question _______ not everyone can understand fully.
| A．How; that | B．That; which |
| C．That; which | D．What; that |
It isn’t quite ___ whether the Tibetan antelope is still being hunted.
| A．certain | B．sure | C．safe | D．careful |
---Where’s the little elephant?
---It’s said it ___ in the hospital.
| A．was examined | B．will be examined |
| C．is being examined | D．has been examined |
She wondered what use she would _______ this chance.
| A．made | B．make about | C．make for | D．make of |
_____ learn more knowledge, the students stay at school on Sunday.
| A．In order to | B．So as to | C．In order that | D．So that |
The two companies are competing ___ each other to get into the Chinese market.
| A．to | B．for | C．in | D．against |