第二部分英语知识运用（共两节，满分45分）
第一节单项填空（共15小题；每小题1分，满分15分）
21. As is known to all, ______ great scientific achievements may have ______ positive effect on our life as well as society.
A. /;a B. the; a C. the; / D. /;the
22. In the process of ________some birds lost the power of flight.
A. revolution B. evolution C. construction D. destruction
23. Professor Karl is a scientist whose experiments have ________ the amazing ways.
A. threw light on B. thrown great light on
C. thrown a great light on D. thrown a light upon
24. Do you agree to the plan ______at the meeting the other day?
A. to put forward B. putting forward C. put forward D. to be put forward
