Nowadays, most people，in order to keep fit，prefer walking to driving ____necessary.
| A．if | B．unless | C．in case | D．as if |
The explorer got a disease in blood for the of fresh vegetables and fruit.
| A．sake |
| B．lack |
| C．ignorance |
| D．benefit |
To achieve your goal,yourself and your direction the most important thing.
| A．knowing;is |
| B．to know; were |
| C．know; was |
| D．and know; are |
Scientists ______ thousands of chemicals before they decided on the right one in the end.
| A．tried out |
| B．found out |
| C．worked out |
| D．turned out |
What Mr. White said sounds ______ .
| A．friendly |
| B．wonderfully |
| C．pleasantly |
| D．nicely |
It's obvious that the experiment ______ a great success.
| A．kept |
| B．showed |
| C．proved |
| D．remained |