21. The old paper mill has been ________ to make way for a new shopping centre.

A) held down B) kept down C) cut down D) turn down

22. It may be necessary to stop ________ in the learning process and go back to the difficult points in the lessons.

A) at a distance B) at intervals C) at case D) at length

23. You can hire a bicycle in many places. Usually you‘ll have to pay a ________.

A) deposit B) deal C) fare D) fond

24. My grandfather had always taken a ________ interest in my work， and I had an equal admiration for the stories of his time.

A) splendid B) weighty C) vague D) keen

25. ________ quantities of water are being used nowadays with the rapid development of industry and agriculture.

A) Excessive B) Extensive C) Extreme D) Exclusive

DBADA