用可再生的物质制备乙酸乙酯的绿色合成路线之一如下图所示：
下列说法正确的是
A．常温下，M能与银氨溶液发生反应
B．④的反应类型属于酯化反应，不属于取代反应
C．用饱和碳酸钾溶液能鉴别乙醇、乙酸和乙酸乙酯．
D．淀粉和纤维素的化学式均为（C6H10O5）n，二者互为同分异构体
答案：C
由题知，M是葡萄糖，在加热条件下发生银镜反应；反应④是酯化反应，也可看做是取代反应；用饱和碳酸钠溶液可以吸收乙醇，反应乙酸。淀粉和纤维素虽通式一样，但n值不同，不是同分异体。
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| These days computer games have become more and more popular in many cities and towns. A lot of small shops along busy 1 have changed into computer game houses in order to get more 2 . These places are always crowded with people. In the computer game houses, people 3 a lot of money matching on the machines. It's 4 for one to beat a computer, but one can do well after trying again and again. People want to 5 when they play computer games. The more they 6 , the more they want to win, and at last they even can't 7 without it. The result is that some people don' t want to 8 , and they play in computer game houses for hours and hours. For school boys, things are 9 . They don't want to have 10 . When school is over, they rush to the computer game houses near their 11 . Some of them can get enough money from their 12 . Some of them are 13 enough to get the money. So they have to steal or rob others' and become 14 . Computer game addiction (上瘾) is a 15 problem in our life. Something has to be done to stop it. | ||||
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