题干

某石灰石厂实验室用5.55g石灰石样品高温煅烧制得生石灰和二氧化碳分析,该实验室进行了四次高温中加热,并冷却后称量,记录数据如表(杂质不参加反应).

操作次数

1

2

3

4

剩余固体质量(g)

4.25

3.95

3.35

3.35

计算:

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同类题1

阅读下面短文,从短文后各题所给的四个选项(A、B、C和D)中,选出可以填入空白处的最佳选项。

    One of the easiest things in the world is to become a fault-finder. However, life can be 1when you are not busy finding fault with it.

    Several years ago I2a letter from seventeen-year-old Kerry, who described herself as a world-class fault-finder, almost always3by things. People were always doing things that annoyed her, and 4was ever good enough. She was highly self-critical and also found fault with her friends. She became a really 5person.

    Unfortunately, it took a horrible accident to change her 6.Her best friend was seriously hurt in a car crash. What made it almost 7to deal with was that the day before the8, Kerry had visited her friend and had spent the whole time criticizing her9of boyfriends, the way she was living, the way she related to her mother, and various other things she felt she needed to 10It wasn't until her friend was badly hurt that Kerry became 11her habit of finding fault. Very quickly, she learned to appreciate life rather than to 12everything so harshly ( 刻薄) . She was able to transfer her new wisdom to other parts of her13as well.

    Perhaps most of us aren't as extreme at fault-finding, 14when we're honest, we can be sharply 15of the world. I'm not suggesting you16problems, or that you pretend things are17than they are, but simply that you learn to allow things to be as they are—18most of the time, and especially when it's not a really big19.

    Train yourself to "bite your tongue" , and with a little20 you'll get really good at letting things go. And when you do, you'll get back your enthusiasm and love for life.