问题 阅读理解

阅读理解。

     It's important to prepare(准备) for earthquakes because you don't know where you will be when an

earthquake happens. Earthquakes may happen at any time, so prepare some things for your home, office

and car.

     1. Clothes.

     If you live in a cold place, you must keep warm. You might not have heat after an earthquake. Think

about your warm clothes.

     2. Flashlights (手电筒) and spare batteries.

     Keep a flashlight beside you bed, at your office and in your car. Do not use matches (火柴) after an

earthquake until you are sure that no gas leaks (气体泄漏).

     Prepare a radio and some spare batteries. Most telephones will be out of order, so radios will be your

best source of information (信息来源).

     3. Food and medicine.

     It's always a wonderful idea to keep some food on hand. For example, some biscuits, some canned

food, milk and some other drinks for at least 72 hours. You'd better get some necessary medicine for

your family.

     4. Water.

     A person needs at least 1/2 gallon (加仑) of water daily just for drinking. Store at least 1 gallon of

water for a person every day and be prepared for 72 hours. It is suggested that you buy bottled water.

Do not open the bottle until you need it. Also, do check the "use by" date.

1. Why should people prepare themselves for an earthquake?

A. Because earthquakes can be know before they happen.

B. Because earthquakes usually take place in the neighborhood.

C. Because we don't know when and where an earthquake will happen.

2. If you live in a cold place, you should prepare _____.

A. some hot water

B. some warm clothes

C. some batteries

3. According to the article we know that _____.

A. we need to prepare some things only at home

B. a telephone is the most important source of information

C. flashlights but not matches are first used after earthquakes

4. You should prepare all of the following except _____.

A. milk

B. fresh vegetables

C. biscuits

5. About the water, which description is RIGHT?

A. A person should drink at least 1 gallon of water in a day.

B. You shouldn't open the bottled water until you need it.

C. You'd better keep some hot water for 72 hours.

答案

1-5 CBCBB

选择题
问答题

某兴趣小组在实验室用加热乙醇、浓H2SO4、溴化钠和少量水的混合物来制备溴乙烷,检验反应的部分副产物,并探究溴乙烷的性质.

(一)溴乙烷的制备及产物的检验:设计了如图1装置,其中夹持仪器、加热仪器及冷却水管没有画出.请根据实验步骤,回答下列问题:

(1)仪器A的名称是______.

(2)制备操作中,加入的少量的水,其目的是______.(填字母)

a.减少副产物烯和醚的生成

b.减少Br2的生成

c.减少HBr的挥发

d.水是反应的催化剂.

(3)加热片刻后,A中的混合物出现橙红色,该橙红色物质可能是______.

(4)理论上,上述反应的副产物还可能有:乙醚(CH3CH2-O-CH2CH3)、乙烯、溴化氢等.

①检验副产物中是否含有溴化氢:熄灭酒精灯,在竖直冷凝管上方塞上塞子、打开a,利用余热继续反应直至冷却,通过B、C装置检验.B、C中应盛放的试剂分别是______、______

②检验副产物中是否含有乙醚:通过红外光谱仪鉴定所得产物中含有“-CH2CH3”基团,来确定副产物中存在乙醚.请你对该同学的观点进行评价:______

(5)欲除去溴乙烷中的少量杂质Br2,下列物质中最适合的是______.(填字母)

a.NaIb.NaOHc.NaHSO3d.KCl

(二)溴乙烷性质的探究:

用如图2实验装置(铁架台、酒精灯略)验证溴乙烷的性质:

Ⅰ:在试管中加入10mL6mol/LNaOH溶液和2mL溴乙烷,振荡.

Ⅱ:将试管如图2所示固定后,水浴加热.

(1)观察到______现象时,表明溴乙烷与NaOH溶液已完全反应.

(2)为证明溴乙烷在NaOH乙醇溶液中发生的是消去反应,将生成的气体通入如图3装置.A试管中的水的作用是______,若无A试管,B试管中的试剂应为______.