题干

某重要有机合成中间体X的结构如图所示,有关该物质的说法正确的是(    )

A:X分子中所有碳原子一定共面

B:X可以使溴水、酸性KMnO4褪色,且原理不相同

C:标况下1 molX分别和足量Na和NaHCO3反应,生成气体体积相同

D:X与庚二酸( )互为同分异构体

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答案(点此获取答案解析)

B

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Three Feet From Gold

    Darby's uncle was caught by the “gold fever” in the gold-rush days, and went west to dig and grow rich. After months of labor, he was rewarded by the discovery of the shining ore (矿石). He needed machinery to bring the ore to the surface. So, with the “strike”, he returned home. And with the help of Darby, he borrowed a lot of money. After buying the machinery and having it shipped, Uncle and Darby went back to work the mine.

    The first car of ore was mined. And the returns proved they had one of the richest mines in Colorado! Down went the drills! Up went the hopes of Uncle and Darby!

    Then something happened! The vein (矿脉) of gold ore disappeared! They drilled on, but all in vain. Finally, they decided to quit and sold the machinery to a junk man for a few hundred dollars. The junk man called in a mining engineer to look at the mine and do a little calculating. The engineer's calculations showed that the vein would be found just three feet from where the Darbys had stopped drilling! The junk man took millions of dollars in the vein, because he knew enough to seek expert's advice before giving up.

    Most of the money which went into the machinery was borrowed through the efforts of Darby, who was then a very young man. The money came from his relatives because of their faith in him. He paid back every dollar of it, although he was years in doing so.

    Long afterward, Mr. Darby made another discovery that desire can be changed into gold. This discovery came after he went into the business of selling life insurance. Remembering that he lost a huge fortune, for he stopped three feet from gold, Darby profited by the experience in his chosen work, saying to himself, “I stopped three feet from gold, but I will never stop because men say 'no' when I ask them to buy insurance.”

    Darby sold more than a million dollars in life insurance annually. He owes his “stickability” to the lesson he learned from his “quitability” in the gold mining business.