_________ life will continue on the earth for millions of years to come will depend on __________ this problem can be solved.
| A．If; that | B．Whether; if |
| C．If; whether | D．Whether; whether |
Mary had promised to give me a ticket for tomorrow. She failed, ____.
| A．either | B．though | C．but | D．too |
_______ different life today is ________ what it was 30 years ago.
| A．How; from | B．What a; from |
| C．What; from | D．How; with |
The time he has devoted in the past years _______ the disable is now considered ________ of great value.
| A．to help; being | B．to helping; to be |
| C．to help; to be | D．helping; being |
I don’t think you can ______ the old man to change his mind.
5.
| A．advise | B．suggest | C．let | D．persuade |
Could you please shut the door; the noise outside ______ the speaker’s voice.
| A．drowns | B．chokes | C．buries | D．fills |