—Car prices have been going down sharply in the last 20 years.—It’s not surprising because

问题补充：

—Car prices have been going down sharply in the last 20 years.

—It’s not surprising because the law of market the price of a product

A. is controlling

B. controls

C. has controlled

D. controlled

答案：

A. is controlling

(答案→)B. controls

C. has controlled

D. controlled

解析：考查时态。在英语中客观真理都使用一般现在时来表示，句意：—在过去的里汽车的价格下降了很多。—这不奇怪，因为市场规律能够控制一个产品的价格。故B正确。