_____ is known to us all is that the old scientist, for _____ life was hard in the past, still works very hard in his eighties.
| A．As; whom | B．What; whom | C．It; whose | D．As; whose |
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 |
To their great ______ , Tom's problem proved not to be as serious as they had feared.
| A．happy |
| B．worry |
| C．anxiety |
| D．relief |