It makes great sense to check and ____________ the brakes（刹车）regularly.
| A．adjust | B．adopt | C．adapt | D．apply |
The result is very important.It is supposed ______ a secret between you and me.
| A．to be kept | B．to keep | C．being kept | D．keeping |
Knowledge and learning are important if we want to be successful, but they may also ________our thinking.
| A．direct | B．limit | C．change | D．improve |
The harder you ________， the better progress you ________.
| A．will work; will make | B．work; have made |
| C．work; will make | D．will work; make |
Professor Smith is now ________ the company, which was once________ Professor White.
| A．in charge of; in charge of | B．in charge of; in the charge of |
| C．in the charge of; in the charge of | D．in the charge of; in charge of |
He is an old doctor with a lot of ________. But he has never travelled by air before.Taking a plane was quite ________ experience for him this time.
| A．experience; an | B．experiences; an | C．experience; / | D．experiences; / |