题干

将等物质的量的X、Y气体充入一个容积可变的密闭容器中,在一定条件下发生如下反应并达到平衡:X(g)+Y(g) 3Z(g) △H<0。当改变某个条件并维持新条件直至达到新平衡,下表中关于新平衡与原平衡的比较,正确的是(  )
选择
改变的条件
正、逆反应速率变化
新平衡和原平衡比较
A
增大压强
正、逆反应速率都增大量
Z的浓度减小
B
充入少量Z
逆反应速率增大
X的体积分数不变
C
充入少量Z
v(逆)>v(正)
Z的浓度减小
D
升高温度
逆反应速率增大量大于
正反应速率增大量
Z的体积分数变大

A:A

B:B

C:C

D:D

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答案(点此获取答案解析)

B

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    My students often tell me they don't have “enough time” to do all their schoolwork. My reply is often brief—You have as much time as the president. I usually carry on a bit about there being 24 hours in the day for everyone, and suggest that “not enough time” is not an acceptable explanation of not getting something done.

    Once in graduate school, I tried to excuse myself to one of my professors by saying that I was working hard. His answer to me was, “That's irrelevant. What's important is the quality of your work.” Since then I have had time to think about the “hard worker” dodge (伎俩), and I have come to some conclusions — all relevant to the issue of how much time we have.

    If you analyze(分析) the matter, you can identify(确定) two parts of the problem: There is, of course, the matter of “time”, which we can think of as fixed. Then there is the problem of “work” during that time. But, as my professor suggested, it's not how hard one works but the quality of the product that is important.

    That led me to a new idea: the quality of the work. That concept is perhaps best explained by a sign I once saw on the wall in someone's office---Don't work harder but work smarter. There's a lot of sense in that idea.

    If you can't get more time, and few of us can, the only solution(解决方法) is to improve the quality of the work. That means thinking of ways to get more out of the same time than we might otherwise get. That should lead us to an analysis of our work habits. Since “work” for students usually means “homework”, the expression “work habits” should be read as “study habits”.

    Then, as a smart student, you will seek to improve those skills that you use in study, chiefly reading and writing. If you learn to read better and write better, there are big benefits that pay off in all your studies.