[单项选择]What is e-books' negative impact on social relationships A. They create new jobs only for writers. B. Fewer and fewer people have access to new technology. C. They may threaten some traditional trades. D. They isolate people from one another.
参考答案:C 答案解析:本题为细节理解题。文章第二段第一句指出电子书将会displace workers in print book production and traditional publishing,即“取代传统的
第24题: [单项选择]The teacher as well as the students ______ looking forward to the summer holiday. A. are B. is C. were D. do 参考答案:B 答案解析:[解析] 考查主谓一致。句子谓语动词的单复数形式与as well as前面的主语保持一致.这里的主语是the teacher,故谓语动词用单数,选B。
第25题: [单项选择]关于醚类化合物错误的说法是() A. 醚类化合物有孤对电子 B. 醚类化合物能吸引质子 C. 醚类化合物具有亲水性 D. 硫醚类化合物可被氧化为亚砜或砜 E. 醚类化合物与受体的结合能力较硫醚类化合物强 参考答案:E 答案解析:醚类化合物由于醚中的氧原子有孤对电子,能吸收质子,具有亲水性,碳原子具有亲脂性,使醚类化合物在脂-水交界处定向排布,易于通过生物膜。硫醚类化合物可被氧化为亚砜或砜,其极性强于醚类化合物,故同受体结合的