题干

为了防止钢铁腐蚀,下列防护方法正确的是(  )

A:在精密机床的铁床上安装铜螺钉

B:在排放海水的铁闸门上用导线连接一块石墨,一同浸入海水中

C:在海轮舷上用铁丝系住锌板浸在海水里

D:在电动输油管的铸铁管上接直流电源的正极

上一题 下一题 0.0难度 选择题 更新时间:2019-07-16 01:52:36

答案(点此获取答案解析)

C

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    When we think about happiness, we usually think of something surprising and unexpected, a top great delight.

    For a child, happiness has a magic quality. I remember playing police and robbers in the woods, getting a speaking part in the school play. Of course, kids also experience lows, but their delight at tops of pleasure is easily seen, such as winning a race or getting a new bike.

    For teenagers, or people under 20, the idea of happiness changes. Suddenly it's conditional on such things as excitement, love, and popularity. I can still feel the pain of not being invited to a party that almost everyone else was going to. I also recall the great happiness of being invited at another event to dance with a very handsome young man.

    In adulthood the things that bring great joy — birth, love, marriage — also bring responsibility and the risk of loss. Love may not last; loved ones die. For adults, happiness is complex.

    My dictionary explains “happy” as “lucky” or “ fortunate”, but I think a better explanation of happiness is “ the ability to enjoy something”. The more we can enjoy what we have, the happier we are. It's easy for us not to notice the pleasure we get from loving and being loved, the company of friends, the freedom to love where we please, and even good health. Nowadays, with so many choices and much pleasure, we have turned happiness into one more thing we have. We think we own the right to have it, which makes us extremely unhappy. So we try hard to get it and consider it to be the same as wealth and success, without noticing that the people who have those things aren't necessarily happier.

    While happiness may be more complex for us, the answer is the same as ever. Happiness isn't about what happens to us. It's the ability to find a positive for every negative, and view a difficulty as a challenge. Don't be sad for what we don't have, but enjoy what we do possess.