问题 阅读理解
根据短文内容,从下框的A-F 选项中选出能概括每一段主题的最佳选项.选项有一项为多余项。

1.
There is considerable variety in university classrooms in the United States. Because of diverse teaching
methods and non-standardized curricula (课程), no two courses are the same.    Undergraduate courses
are considerable different from graduate courses. The classroom atmosphere in expensive, private
universities may differ from that in community colleges, which are free and open to everyone.
2.
Participation in the classroom is not only accepted but also expected of the student in many courses.
Some professors base part of the final grade on the student's oral participation. Although there are formal
lectures during which the student has a passive role (i.e., listening and taking notes), many courses are
organized around classroom discussions, student questions, and informal lectures.
3.
Many teachers believe that the responsibility for learning lies with the student. (Courses are not designed
merely for students to pass exams.) The ideal student is considered to be one who is motivated to learn
for the sake of learning, not the one interested only in getting high grades.
4.
Ideally, the teacher-student relationship at universities is characterized by trust. Thus, cheating on tests,
Plagiarizing (抄袭) in written work, presenting other's ideas as original, and turning in homework
completed by someone else are all prohibited (禁止).
5.

Relationships between students in the classroom can be cooperative or competitive. International
students should not hesitate to ask for help if it is needed. in classes where such a grading curve is used,
students may be reluctant to share lecture notes or information for fear that their own grades will suffer.

答案

1-5BACED

选择题
问答题

近期研究证实,中药甘草中的异甘草素在药理实验中显示明显的促进癌细胞凋亡和抑制肿瘤细胞增殖的活性,且对正常细胞的毒性低于癌细胞.异甘草素可以由有机物A和有机物B合成(A、B均为芳香族含氧衍生物),且由A和B合成异甘草素要用到以下反应:

请回答下列问题:

(1)有机物B分子式为C7H6O2,A和B均能与浓溴水反应生成沉淀.A和B具有一种相同的含氧官能团,其名称为______;B的核磁共振氢谱有四个峰,峰面积之比是2:2:1:1.以下说法正确的是______(填序号).

①有机物B能发生很多类型的反应,例如:中和、取代、氧化、还原、加成反应

②与B互为同分异构体的芳香族含氧衍生物共有两种(不含B)

③B能与碳酸氢钠溶液反应放出二氧化碳气体

(2)质谱表明有机物A相对分子质量为152,其碳、氢、氧元素的质量分数比为12:1:6.有机物A的分子式为______;已知A发子中的官能团均处于间位,写出A、合成异甘草素的化学方程式______.

(3)初步合成的异甘草素需要经过以下处理工艺;

I加入一定量的水,再加入一定量的乙醚提取2次

II用无水MgSO4干燥、过滤减压蒸出.

III洗涤、浓缩得黄色粉末,再用含水乙醇处理得黄色针状晶体.

步骤II蒸出的物质可能是______.以上处理工艺中涉及的分离提纯操作依次有______.

(4)有机物D符合下列条件,写出D的结构简式______.

①与A互为同分异构体,且能发生水解反应②1molD能与3moNaOH反应③苯环上的氢被氯取代的一氯代物有两种

(5)有机物E生成F的方程式:______.