问题 选择题

α-鸢尾酮香料的分子结构如右图,下列说法不正确的是

A.α-鸢尾酮可与某种酚互为同分异构体

B.1molα-鸢尾酮最多可与3molH2加成

C.α-鸢尾酮能发生银镜反应

D.α-鸢尾酮经加氢→消去→加氢三步反应可转变为:

答案

答案:C

本题考查有机物的结构与性质。该物质的分子中存在3个双键和一个环,与苯环的不饱和度相同,所以与酚为同分异构体,A选项正确;3个双键都能与氢气发生加成反应,B选项正确;该物质的分子中不存在醛基,C选项错误;首先加氢是碳碳双键和碳氧双键的加成,得到,然后发生醇的消去,得到烯烃,最后烯烃的加成得到,D选项正确。

单项选择题

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。选项中有两项为多余选项。

A garden that’s just right for you

Have you ever visited a garden that seemed just right for you, where the atmosphere of the garden appeared to total more than the sum(总和) of its parts?    36   . But it doesn’t happen by accident. It starts with looking inside yourself and understanding who you are with respect to the natural world and how you approach the gardening process.

●37  

Some people may think that a garden is no more than plants, flowers, patterns and masses of color. Others are concerned about using gardening methods that require less water and fewer fertilizers(肥料).    38   . However, there are a number of other reasons that might explain why you want to garden. One of them comes from our earliest years.

●Recall(回忆) your childhood memories

Our model of what a garden should be often goes back to childhood. Grandma’s rose garden and Dad’s vegetable garden might be good or bad, but that’s not what’s important.    39   --how being in those gardens made us feel. If you’d like to build a powerful bond with your garden, start by taking some time to recall the gardens of your youth.    40    then go outside and work out a plan to translate your childhood memories into your grown-up garden. Have fun.

40()

A. Know why you garden

B. Find a good place for your own garden

C. It’s our experience of the garden that matters

D. It’s delightful to see so many beautiful flowers

E. Still others may simply enjoy being outdoors and close to plants

F. You can produce that kind of magical quality in your own garden, too

G. For each of those gardens, writer down the pest memory you have

名词解释