(2013·东北三校4月联考)—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 句意：“汽车的价格在过去的20年急剧下降。”“这一点也不奇怪，因为市场规律决定产品的价格。”“市场规律决定产品的价格”说的是一个客观事实，因此用一般现在时。