下列做法能达到目的是( ) A.制取氢氧化铜Cu(OH)2:将NaOH溶液与Cu

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问题:

下列做法能达到目的是(  )

A.制取氢氧化铜Cu(OH)2:将NaOH溶液与CuSO4溶液混合后过滤

B.用Ba(NO32能把KOH溶液、稀硫酸、CaCl2溶液一次鉴别出来

C.清洗试管中附着的铜:向试管中注入稀硫酸,振荡

D.鉴别硫酸铵和氯化铵两种氮肥:分别与熟石灰混合后研磨,闻气味

考点:化学实验方案设计和实验现象的分析化肥酸的性质碱的性质物质的鉴别
题型:选择题

__小题1:___ People use money to buy food, furniture, books, bicycles and hundreds of other things they need or want. When they work, they usually get paid in money.

Most of the money today is made of metal or paper.___小题2:___ One of the first kinds of money was shells.

Shells were not the only things used as money.In China, cloth and knives were used. In the Philippine Islands, rice was used as money for a long time.Elephant tusks, monkey tails and salt were used as money in parts of Africa.

The first metal coins were made in China.They were round and had a square hole in the centre. ___小题3:____

Different countries have used different metals and designs for their money.___小题4:___ Sweden and Russia used copper (铜) to make their money. Later some countries began to make coins of gold and silver.

But even gold and silver were inconvenient if you had to buy something expensive. Again the Chinese thought of a way to improve money.____小题5:_____The first paper money looked more like a note from one person to another than the paper money used today.

Money has had an interesting history from the days of shell money until today.

A.The first coins in England were made of tin (锡).

B.But people used to use all kinds of things as money.

C.No one knows for certain when people began to use money.

D.People strung (串连) them together and carried them from place to place.E. Money, as we know, is all made of paper.

F. They began to use paper money.

G. Today anyone will accept money in exchange for goods and services.

题型:选择题

土家族一般说请客人吃茶是指()。

A.喝茶

B.喝奶茶

C.吃油茶

D.喝水

题型:选择题

设[*],求y’.

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收集的工程文件资料应检查各项内容填写规范性和记录真实完整性,签字认可人员应为符合相关规定的()。

A.总监理工程师

B.项目技术负责人

C.资料员

D.责任人员

题型:选择题

当转子产生的电磁转矩与其他机械作用在转子轴上的负载阻转矩相等时,转子就以()速转动。

A、加

B、等

C、减

D、不确定

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