1 . 在过去的二十年到三十年里里,鲨鱼的数目已经下降了90﹪. (drop)
The number of the sharks ______________________ by 90﹪in the past 20 to 30 years.

2 . His grades _____________ (drop) because he spent too much time playing computer games.

3 . She didn't do well in the test. She ______ to tell her parents the truth.

A．hoped

B．feared

C．allowed

D．dropped

4 . 气温会降到零下。
The temperature can ________.

5 . 随着白天的时间变短，气温逐渐下降。
________ the days are shorter, ________.

6 . As the temperature keeps d________ these days, you'd better wear more clothes to keep warm.

7 . He lost himself in computer games. As a result, his math grades d________.

8 . Work hard,or your grades will ________(下降).

9 . In autumn, the day is shorter and the temperature________(下降).

10 . In China, cash use _________ (drop) because of the increasing popularity of electronic payment services over the past ten years.