—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
网友回答
A. is controlling
(答案→)B. controls
C. has controlled
D. controlled
解析：B 考察动词时态。由语境可知，市场规律控制商品价格，这是一个客观真理，因此应该使用一般现在时。故B正确。