食管癌主要为（）
A.小细胞未分化癌
B.鳞癌
C.腺癌
D.神经内分泌癌
E.鳞腺癌
参考答案：B
制定政府指导价和政府定价的基本依据是( )。
A．市场供求状况 B．社会平均成本C．社会承受能力 D．国民经济与社会发展的要求
We are pleased to know that you have planned to come to the Autumn Guangzhou Fair. We wish to discuss with you some other important things if you could come ______ your earliest convenience.
A．by B．onC．in D．at
