From the ________ look on his face, we know that the price of meat _________. [      ]

A. disappointed; has been gone up    

B. disappointed; has been raised   

C. disappointing; has gone up        

D. disappointing; has risen

可以用来鉴别甲烷和乙烯，还可以用来除去甲烷中乙烯的操作方法是[ ]

A．将混合气体通过盛有酸性高锰酸钾溶液的洗气瓶

B．将混合气体通过盛有适量溴水的洗气瓶

C．将混合气体通过盛有水的洗气瓶

D．将混合气体通过盛有澄清石灰水的洗气瓶