题干

以下是某研究小组探究影响化学反应快慢的一些因素的相关数据.

实验序号

过氧化氢溶液浓度/%

过氧化氢溶液质量/g

温度/℃

二氧化锰用量/g

氧气体积/mL

反应所需时间/s

5

12

20

0.2

125

11

30

12

20

0.2

125

2

30

12

40

/

125

148

30

12

90

/

125

82

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    Here are six steps to better studying.

Pay attention in class

    Do you have trouble paying attention in class? Are you sitting next to a loud person? Tell your teacher or parents about any problem that is preventing you from paying attention.

Take good notes

    Write down facts that your teacher mentions or writes on the board. Try to use good handwriting so you can read your notes later. It's a good idea to keep your notes organized by subject.

Plan ahead for tests and projects

    Waiting until Thursday night to study for Friday's test will make it hard to do your best. One of the best ways to make sure that doesn't happen is to plan ahead. Write down your test dates. You can then plan how much to do after school each day, and how much time to spend on each topic.

Break it up

    When there's a lot to study, it can help to break things into several parts. Let's say you have a spelling test on 20 words. Instead of thinking about all of the words at once, try breaking them down into five-word groups and work on one or two different groups each night.

Ask for help

    You can't study effectively if you don't understand the material. Be sure to ask your teacher for help. If you're at home when the confusion occurs, your mom or dad might be able to help.

Sleep tight

    So the test is tomorrow and you've followed your study plan—but suddenly you can't remember anything! Don't panic. Your brain needs time to digest all the information you've given it. Try to get a good night's sleep and you'll be surprised by what comes back to you in the morning.