Cholera was such a d________ （致命的）disease that many people died of it.
After they had studied for years, they a____（宣布）with certainty that they found out the reason.
She was c________ （谨慎）to avoid making her father angry.
School must meet the c________ （挑战）of the new technology.
Loose clothing can give you greater freedom of m_______ （移动）.
The scientists are doing s___________ ( science) research on the rats.
Everyone should c______ (捐献,贡献) what he or she can afford to help the poor.
All the other candidates were d_______ (击败) by him in the election. So he won the election.
It is a great ____________( convenient) to have a cell phone.
To be honest， I can't tell what the ________ ( attract) of this famous painting has.
I want to c________ (澄清) my reasons for not having attended the meeting.
He ___________ (constant) suffered from lack of preparation.
There were so many carriages that I lost s________of (看不见)Wang Ping.
Animals in zoos are not in their natural s_________(环境).
The new teacher made a good i__________ (印象) on the students.