题干

如图有机物分子中带“*”碳原子是手性碳原子(连有四个不同基团的碳原子)。该有机物分别发生下列反应,生成的有机物分子中不会含有手性碳原子的是

①与甲酸发生酯化反应          ②与足量NaOH水溶液反应
③与银氨溶液作用只发生银镜反应   ④催化剂作用下与H2反应

A:①②③④

B:①③

C:②④

D:以上反应都不成立

上一题 下一题 0.0难度 选择题 更新时间:2016-12-19 07:34:17

答案(点此获取答案解析)

C

同类题2

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。

    It is important to introduce yourself in a creative, memorable way to distinguish yourself from the crowd. ____ Since being witty(言辞诙谐的) doesn't always come easily, try one of these creative introductions and separate yourself from the rest.

    Write your first or last name on a piece of paper.____ So if your name is Tom, you might say you are tireless, optimistic and mild.

    ____ Then say that you will do so in the words of your“best and worst critic”— your mother. By breaking the ice in this way, you can go on in either a humorous or serious fashion.

    Introduce yourself silently, by drawing a picture of yourself on a large sheet of paper.____  In fact, in some situations, it may be better if you don't. Put a title at the top of your drawing, if you like, such as “Hello! This is me.”

    Turn the traditional introduction upside down by describing yourself in exactly opposite terms of who you are. Have fun with this“back door approach”, and keep people guessing just how much you are exaggerating(夸张).____  Don't bother calling me tomorrow, because I will be hiding in a closet. Send text messages to my girlfriend while I drink a Bud Light on the job.

A. This introduction requires you to be gifted in art.

B. Freely admit that you don't like talking about yourself.

C. It doesn't matter whether you have artistic abilities or not.

D. For example: I am probaby the laziest person you will ever meet.

E. Use each letter as the first letter in an adjective that describes you.

F. Bring in the surprise factor— sometimes known as the shock factor.

G. After all, anybody can stand up and announce their name, business title and job responsibilities.