题干

预防和治疗甲型H1N1流感的中草药中都含有金银花。绿原酸是金银花的活性成分之一,具有广泛的抗菌及抗病毒作用。有关绿原酸的说法不正确的是

A:绿原酸的分子式为C16H18O9

B:1 mol绿原酸最多可与6 mol H2发生反应

C:绿原酸中含氧官能团有羧基、羟基和酯基

D:绿原酸酸性条件下水解后所得两产物碳原子数之差为2

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B

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    Failure is probably the most exhausting experience a person ever has. There is nothing more tiring than not succeeding.

    We experience this tiredness in two ways: as start-up fatigue (疲惫) and performance fatigue. In the former case, we keep putting off a task because it has either too boring or too difficult. And the longer we delay it, the more tired we feel. Such start-up fatigue is very real, even if not actually physical, not something in our muscles and bones. The solution is obvious though perhaps not easy to apply: always handle the most difficult job first.

    Years ago, I was asked to write 102 essays on the great ideas of some famous authors. Applying my own rule, I determined to write them in alphabetical (按字母顺序), never letting myself leave out a tough idea. And I always started the day's work with the difficult task of essay-writing. Experience proved that the rule works.

    Performance fatigue is more difficult to handle. Though willing to get started, we cannot seem to do the job right. Its difficulties appear so great that, however hard we work, we fail again and again. In such a situation, I work as hard as I can — then let the unconscious take over.

    When planning Encyclopaedia Britannica (《大英百科全书》), I had to create a table of contents based on the topics of its articles. Nothing like this had ever been done before, and day after day I kept coming up with solutions, but none of them worked. My fatigue became almost unbearable.

    One day, mentally exhausted, I wrote down all the reasons why this problem could not be solved. I tried to convince myself that the trouble was with the problem itself, not with me. Then, I sat back in an easy chair and fell asleep.

    An hour later, I woke up suddenly with the solution clearly in mind. In the weeks that followed, the solution which had come up in my unconscious mind provided correct at every step. Though I worked as hard as before, I felt no fatigue. Success was now as exciting as failure had been depressing.

    Human beings, I believe, must try to succeed. Success, then, means never feeling tired.