① ②  ③  ④ (1)上图所示装置中,_ 可用于实验室制取并收集O

题型:实验题

问题:

 

①      ②       ③     ④

(1)上图所示装置中,  _     可用于实验室制取并收集O2(使用氯酸钾和二氧化锰制取O2);      _ 可用于实验室制取并收集H2          可用于实验室制取并收集CO2。(填写装置的编号,要求将所有可使用的装置全部写出)    

(2)写出使用氯酸钾和二氧化锰制取氧气的化学方程式:            。    

(3)检验上述装置③中集气瓶里的气体是否已充满的方法是: ___   

(4)当上述装置②中将气体收集满并取出集气瓶后,停止实验的正确操作步骤是:     __ 

考点:氧气的制取和收集化学实验操作的注意事项氢气的制取和收集二氧化碳的制取和收集二氧化碳的检验和验满
题型:实验题

阅读理解。

     In 1837, the historian Carlyle made the first recorded use of the word "queue" (排队). He spoke of the

French and their "habit of standing in a queue". Forty years later Paris was the best place to wait in line.

     However, queuing became popular in Britain too. The Second World War was the golden age of queuing,

and people joined any line in the hope that it was a queue for something to buy. This was the source of many

Second World War jokes:

      Shopkeeper to customer: Excuse me, miss, are you pregnant (怀孕)?

     Customer: Well, I wasn't when I joined the queue.

     Today, according to research in America, we (in Britain) can spend up to 5 years of our lives queuing-as

compared to twelve months looking for things we have lost. But things may be changing. Many people no

longer have the patience to stand in a queue. The law of the jungle (丛林) has begun to operate at bus stops,

with people using their arms to push others out of the way.

     One way to make life easier is to introduce "queue management". Customers at supermarket cheese

counters can now take a ticket with a number which appears on a screen when it is their turn. And while they

wait for their number, they can do a bit of shopping. In some booking offices there is also a system telling

customers how long they may have to wait before they are served.

     One of the latest technical progress is the use of an electronic scanner (电子识别器) which can read all

the contents of your shopping basket or trolley in just a few seconds. If these become popular, queuing in

supermarkets may become a thing of the past.

     But some people just like queuing. One man queued all night for Harrods famous January sale, and then

returned home for breakfast at nine o' clock the next morning without going into the shop.

1. The joke in Paragraph 2 implies that the young woman ______.

A. has been waiting in the queue for a long time

B. doesn't need to stand in the queue

C. enjoys standing in the queue

D. has stood in the wrong line

2. According to the passage, which of the following is true?

A. The British spend more time queuing than looking for lost things.

B. The Americans criticized the British for their way of queuing.

C. The British are always patient when they wait in line.

D. People queue only when they want to buy something.

3. The British try to solve the problem of queuing by all the following EXCEPT _____.

A. making a law to prevent queuing

B. telling the customers the waiting time

C. using numbered tickets to put the customers in order

D. checking the price of the goods customers buy with a scanner

4. We can infer from the passage that ______.

A. queue management doesn't work well

B. there is still queuing in England

C. we don't see much queuing in Paris

D. the French like queuing more than the British

题型:实验题

下列关于RNA的叙述,哪一项是错误的()。

A.主要有mRNA,tRNA和rRNA等种类

B.原核生物没有hnRNA和snRNA

C.tRNA是最小的一种RNA

D.胞质中只有关一种RNA,即tRNA

E.组成核糖体的RNA是rRNA

题型:实验题

更衣室与操作台面()

A.热压灭菌

B.紫外线灭菌

C.干热灭菌

D.滤过除菌

E.流通蒸气灭菌

题型:实验题

接待客人时要从心理上尊重,善待宾客,且应热情()。

A.和蔼可亲

B.极度热情

C.体贴入微

D.温柔温顺

题型:实验题

国家对“导游专座”设置和使用制定了什么文件,有哪些主要内容?

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