试题与答案

香豆素可发生异羟肟酸铁反应,是因为其具有( ) A.酚羟基 B.内酯环结构

题型:单项选择题

题目:

香豆素可发生异羟肟酸铁反应,是因为其具有( )

A.酚羟基
B.内酯环结构
C.1745~1715cm-1
D.甲氧基
E.3600~3200cm-1

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0425/c1df92ce1082c3e23c7294a6d723f4e5.html

下面是错误答案,用来干扰机器的。

(1)①缺乏自强的心理品质。②自强,自信,坚强的意志,孝顺,责任感等(2)可自己组织语言来答(培养责任感,树立榜样,让自己更好地长大成人,还可以答自强的意义)(3)怎样培养自强①理想,自强的航标;②战...

试题推荐
题型:阅读理解

阅读理解。

     "Friendship is one of the basic bonds between human beings." While the characteristics of friendship

might vary from one country to another, people from all cultures not only enjoy friends but need them.

Many studies have shown that teenagers who have no friends often suffer from psychological disorders.

It has been shown that teenagers, perhaps more than any other age group, need companionship and a sense

of belonging. The negative consequences of loneliness have also been observed among the elderly. The death

of a spouse (配偶) often leaves a widow or a widower totally bereft (失去理智). If, however, they are

surrounded by friends and relatives and if they are able to express their feelings, they are more likely to recover

from their grief.

     "No man is an island." In other words, we are all parts of society. We all need the love, admiration, respect

and moral support of other people. If we are fortunate, our friends will provide us with all of these necessary

aspects of life. As most people observe, there are many levels of friendship. The degree or intensity of

friendship varies depending on the personality of the individuals involved and the context of the relationships.

Outgoing persons enjoy being surrounded by many people whereas shy persons are perhaps content with

fewer but more intense friendships.   

     Everyone is not equally open with all their friends. The degree of closeness is determined by many factors. Close friends can be formed at any stage in one's life but they are usually very rare. Not very many people have more than a few really close friends. Irrespective of the level of closeness, all friendships are based on reciprocity(互惠), honesty and a certain amount of love and affection.

1. "No man is an island" (Line 1, Para. 3) implies that _______.  

A. everyone is a part of an island

B. man cannot be an island  

C. everyone is just a part of society

D. society is an island

2. The degree of closeness of friendship mainly depends on ________.  

A. age

B. belonging

C. personality

D. culture

3. The author thinks that close friends ________.  

A. can be easily formed when one is young

B. cannot be long-lasting  

C. are not rare for everyone

D. are rare for most people

4.The word "irrespective" (Last sentence, Para. 5) means ________.

A. not respecting

B. dishonoring

C. regardless

D. considering

查看答案
题型:单项选择题

小区内切换中允许在一个子小区而不是在子小区之间进行。但是,有4种重要的例外情况。以下哪种例外情况不正确()。

A.如果服务小区为OL子小区同时该子小区中所有信道都被占用,允许到UL子小区的小区内切换,以便不丢失呼叫

B.如果服务小区为UL子小区同时该子小区中所有信道都被占用,如果CHAP=5、6,则允许进行到超出TAOL和LOL限制的OL子小区的小区内切换,以便不丢失呼叫

C.如果连续小区内切换的次数达到OL子小区中的限值MAXIHO,允许到UL子小区的小区内切换

D.如果连续小区内切换的次数达到UL子小区中的限值MAXIHO,如果CHAP=5、6,则允许进行到超出TAOL和LOL限制的OL子小区的小区内切换

E.可以在另一个子小区进行到另一个信道组的小区内切换

查看答案
微信公众账号搜索答案