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[判断题]

锌杂质会是镍镀层发脆、产生黑色条纹，严重时镀层会发暗黑。（)

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更多“锌杂质会是镍镀层发脆、产生黑色条纹，严重时镀层会发暗黑。()”相关的问题

第1题

锌镀层低铬蓝白钝化液中加入氰化物可提高钝化液的抛光性能。（)

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第2题

下列说法不正确的是( )。

A.研究商品的化学成分，重点在于研究其主要成分和杂质成分的含量

B.酒精占香水总体的10%，所以酒精是香水的主要成分

C.主要成分叫有效成分，是构成商品使用性能的基本成分

D.有害成分的含量虽然不一定很多，但对商品质量产生严重不良影响

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第3题

下列对锌的叙述何者有误？

A、植酸的存在影响锌的吸收

B、锌的吸收主要发生于十二指肠

C、锌进入肠黏膜之前需与球蛋白结合

D、锌的吸收与Metailothionine有关。

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第4题

中国半殖民地半封建社会是一个政治经济文化发展极不平衡的社会，产生这种不平衡的主要原因是()。

A.民族资本主义有了发展但非常缓慢

B.帝国主义列强在中国划分势力范围

C.中国国土面积广大以及地方性农业经济的广泛存在

D.自给自足的自然经济占据主导地位

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第5题

含NH4Cl、NaIO3和惰性杂质的试样1.878g，溶于水后稀释至250.00mL。吸取50.00mL两份，一份加入过量的AgNO3，产生A

含NH₄Cl、NaIO₃和惰性杂质的试样1.878g，溶于水后稀释至250.00mL。吸取50.00mL两份，一份加入过量的AgNO₃，产生AgCl、AgIO₃沉淀0.6020g；另一份加入过量的Ba(NO₃)₂，产生Ba(103)2沉淀0.1974g。试计算试样中NH₄Cl、NaIO₃的含量。

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第6题

马克思指出：“不管生产力（指生产率引者注)发生了什么变化，同一劳动在同样的时间内提供的

马克思指出：“不管生产力(指生产率引者注)发生了什么变化，同一劳动在同样的时间内提供的价值量总是相同的。但它在同样的时间内提供的使用价值量会是不同的：生产力提高时就多些，生产力降低时就少些。”这表明．在活动不变的情况下，社会或部门劳动生产率提高，单位时间内生产的商数量和价值总量之间的变化表现为

A．商品数量增加，价值总量不变

B．商品数量不变，价值量增大

C．商品数量增加，价值量减少

D．商品数量增加，价值量增大

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第7题

Money is used for buying or selling goods, for measuring value and for storing wealth. Alm

ost every society now has a money economy based on coins and bills of one kind or another. However, this has not always been true. In primitive societies a system of barter was used. Barter was a system of direct exchange of goods. Somebody could exchange a sheep, for example, for anything in the market place that he or she considered to be of equal value. Barter, however, was a very unsatisfactory system because people 's precise needs were seldom met. People needed a more practical system of exchange, and various money systems developed based on goods that the members of society recognized as having value. Cattle, grain, teeth, shells, feathers, salt, elephant tusks, and tobacco had all been used. Precious metals gradually took over because, when made into coins, they were portable, durable, recognizable, and divisible into larger and smaller units of value.

A coin is a piece of metal, usually disc-shaped, which bears words, designs or numbers showing its value. Until the eighteenth and nineteenth centuries, coins were given monetary worth based on the exact amount of metal contained in them, but most modern coins are based on face value—the value that the governments choose to give them, which doesn't show the actual metal content. Coins have been made of gold, silver, copper, aluminum (铝) , nickel(镍) , lead, zinc (锌) , plastic and in China even from tea leaves. Most governments now issue paper money in the form. of bills, which are really" promise to pay". Paper money is obviously easier to handle and much more convenient in the modern world. Checks and credit cards are being used increasingly, and it is possible to imagine a world where "money" in the form. of coins and paper currency will no longer be used. Even today, in the United States, many places, especially filling stations will not accept cash at night for security reasons.

Barter here means ______.

A．exchanging goods for money

B．exchanging sheep for anything in the market

C．exchanging goods for goods

D．exchanging money for goods

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第8题

氰化镀锌溶液中的碳酸盐可使镀层光亮。（)

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第9题

休克引起肺、肾、心、脑功能衰竭，一般发生在休克持续（）A．24h以上 B．48h以上 C．控制严

休克引起肺、肾、心、脑功能衰竭，一般发生在休克持续（）