A. their prices are higher B. people cannot telephone them C. their staff may take less trouble to satisfy customers D. one has to queue up to pay in them 参考答案:C 答案解析:逻辑推理题。第四段叙述乡村小店店员愿为顾客提供多种方便,即暗含城市商店却无此优点。
第29题: [单项选择]经糖异生途径生成葡萄糖时耗能最多的化合物是 A. 甘油 B. 乳酸 C. 谷氨酸 D. 琥珀酸 E. 草酰乙酸 参考答案:E 答案解析:[考点] 糖异生 [分析] 乳酸、谷氨酸及琥珀酸要异生为糖均需先转变为草酰乙酸,后者再转变为磷酸烯醇式丙酮酸,然后沿糖酵解逆行转变成糖。乳酸先脱氢生成丙酮酸,此过程中有 NADH+H+