近年来，轿车价格频频降低，房产价格节节攀升。这表明商品的市场价格（   ）

A．是由商品的质量决定的

B．是买卖双方讨价还价的结果

C．由价值决定并受供求关系影响

D．取决于居民的消费水平和消费结构

- My boss often made me work day and night.

- If I _______ you, I _______ the job. [ ]

A. am, will give up    

B. had been, would have given up

C. were, would give up    

D. had been, would give up