称量法测定黄铁矿中硫含量,称取试样0.3853克,下列分析结果合理的是()。A、36

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问题:

称量法测定黄铁矿中硫含量,称取试样0.3853克,下列分析结果合理的是()。

A、36%

B、36.4%

C、36.41%

D、36.4103%

考点:化学分析工考试化学分析工综合练习化学分析工综合练习题库
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In nature, you may see many insects (昆虫)and animals of different colors. Have you ever wondered why?

Locusts are super delicious food for birds,but it is not always an easy job for birds to catch them.It is neither because locusts are good jumpers or runners nor because they are smarter than their enemies. The reason is that the colors of locusts change with the colors of crops(庄稼). When crops are young,locusts look green. But when autumn comes, locusts change to the yellow and brown color as crops do.

Brown bears,tigers and other animals move quietly through forests. They can’t be seen easily by their enemies. This is because they have colors similar to the trees. For the same reason, polar bears that live on a land of snow and ice are white. Butterflies and bees living among the flowers are colorful like flowers. Soil insects are mostly dark-colored and they live under the soil(土壤) in a dark and wet environment. However, insects with colors different from plants can easily be found and eaten by others. So in order to survive,they have to hide themselves in the daytime and appear only at night.

Have you ever noticed some even stranger acts? The ink fish in the sea can send out some very black ink when it faces danger. As the ink spreads over , its enemies will find themselves suddenly in a dark world. At the same time the ink fish immediately swims away. That is how it keeps itself safe though it is not strong at all.

小题1:It is not easy for birds to catch locusts because____________.

A.locusts are good runners

B.locusts can jump very high

C.locusts are smarter than birds

D.locusts can change their color小题2:According to the passage, most soil insects_________

A.do not have bright colors

B.change their colors with the soil

C.do not live in a dark and wet environment

D.Eat colorful insects like butterflies and bees小题3:What’s the meaning of the underlined word”survive” in the passage?

A.繁殖

B.产卵

C.觅食

D.生存小题4:The ink fish_______so that its enemies will not see it?

A.changes its color

B.makes the water around it black

C.appears only at night

D.hides itself in the sea rocks小题5:What is the main idea of this passage?

A.Some insects and animals have different skills.

B.Some insects and animals are clever than we think.

C.Some insects and animals use colors to protect themselves.

D.Some insects and animals can get used to the environment easily.

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外汇构成的三要素是什么

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在车列、车辆运行中应注意()

A、严禁骑坐车帮、跨越车辆

B、严禁在连接器上或端板支架上站立

C、严禁两人站在同一闸台上

D、严禁在窜动的货物间站立

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上下级间的现金调拨关系通过()交易维护。

A.现金调拨申请(21441)

B.现金申请审批(21443)

C.机构参数维护(31140)

D.机构状态查询(9766)

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防水涂料具有的显著特点是()。

A.抵抗变形能力强

B.有利于基层形状不规则部位的施工

C.施工时不需加热

D.使用年限长

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