有A、B、C、D四种有机物,其组成均是含碳40%、氢6.67%、 氧53. 33

题型:填空题

问题:

有A、B、C、D四种有机物,其组成均是含碳40%、氢6.67%、 氧53. 33%。A的蒸气对氢气的相对密度为15,B的相对分子质量为A的6倍,C、D的蒸气密度折算为标准状下都是2. 68 g/L;A、B物质的水溶液都能发生银镜反应,C物质的水溶液呈酸性,D物质属于酯类。写出A、B、C、D的结构简式和名称。

A:________,________,B:________,________, C:_______,_______,D:________,________.

考点:有机化学的有关计算
题型:填空题

阅读排序。阅读下列各句,根据首句提示,请将选项A-J按其内容重新排列顺序,使其构成意思完整正确、逻辑顺序合理的语篇。(共10 小题,每小题0.5分, 计5分)

A monkey named Monty lived on an island(岛) with his friends. A flood was coming. Every monkey decided to build a house on the highest part of the island.

A.But Monty didn't care because his house needed very big stones.

B.When Monty finished his house, he invited all the monkeys to have a party at his new home.

C.All the monkeys built their houses quickly, and then they spent time playing.

D.On the day of the party, the flood came! All the monkeys were scared.E. The big flood destroyed(摧毁) all the other houses except Monty’ s.

F. They all laughed at Monty because he built his house very slowly.

G. So he went on building his house stone by stone.

H. Monty shouted, "I have prepared for this flood. This house would keep us safe."

I. He believed that his house could keep any flood away.

J. It took him a long time to build the stone house.

Then the monkeys understood that Monty was very clever and kind-hearted, for he wanted to save them without expecting anything in return.

题型:填空题

增大压强的方法是______和______.减小压强的方法是______和______.

题型:填空题

某电力建设公司承建了某发电厂电气设备安装工程。其安装内容主要有:户外降压变压器安装;高压配电柜安装;高压同步电动机安装;断路器安装、用电计量装置的安装;电气设备安装及试运行。在安装过程中,该电力建设公司严格执行相关技术标准、规范,认真做好各阶段、各工序的施工记录,交工验收顺利进行。

户外变压器、断路器固定用的紧固件应采用热()制品。

A.镀铝

B.镀锌

C.镀铜

D.镀铬

题型:填空题

《职业病防治法》规定,最后的用人单位有证据证明该职业病是先前用人单位的职业病危害造成的,由()承担。

A.先前的用人单位

B.先前的和最后的用人单位平均

C.最后的用人单位

D.先前的和最后的用人单位连带

题型:填空题

下列对有关鉴定性实验、观察类实验、探究性实验以及调查类实验的叙述,正确的是()

A.鉴定组织中脂肪的颜色反应实验时,必须使用显微镜

B.观察叶绿体的实验中,可选用洋葱鳞片叶外表皮细胞

C.设计探究酶的专一性实验时,自变量可设置酶的种类不同或者底物不同

D.调查某遗传病的发病率时,一般应选发病率较低的单基因遗传病

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