问题 选择题

下列实验操作中有错误的是  (    )

A.分液时,分液漏斗下层液体从下口放出,上层液体从上口倒出

B.萃取时,用酒精萃取碘水中的碘

C.蒸馏时,冷却水应从冷凝管的下口通入,上口流出

D.把几滴FeCl3饱和溶液滴入25mL的沸水中加热至液体呈红褐色,制取Fe(OH)3胶体

答案

答案:B

题目分析:酒精和水互溶,所以不能用酒精萃取碘水中的碘,而应该用四氯化碳或苯,选项B不正确,其余选项都是正确的,答案选B。

点评:该题是基础性试题的考查,主要是考查学生对常见化学实验基本操作的熟悉了解掌握程度。该题主要是以常见仪器的选用、实验基本操作为中心,通过是什么、为什么和怎样做重点考查实验基本操作的规范性和准确及灵活运用知识解决实际问题的能力。

阅读理解

阅读理解。

     阅读下面的短文。请根据短文后的要求答题(请注意问题后的字数要求)。

1)  One in four people spend more time socializing online, using sites such as Facebook, than they

do in person, according to research.

2)  People now have 11 different ways of staying in contact with their friends from the comfort of

their sofa or bedroom.

3)  These include simple email, messenger, text and several forms of social networking from Twitter

to Facebook, said the survey by online casino Yazino.

4)  It is found even when there is time to see people face to face, like at a weekend, up to 11 percent

of all adults still choose to       .

5) This could be down to laziness, the cost of going out or simply not wanting too much personal

contact with friends and family but just enough to swap brief messages and online chats.

6) It all adds up. The average online Brit spends 4.6 hours a week talking to friends online and only

six hours a week talking to people in person, said Yazino.

7) There is even an army of "extreme sofalisers"-the three percent who spend a staggering 25 hours

or more each week talking to friends via electronic devices.

8) The survey of 2, 000 adults also found 11 percent organize all their social diary around Facebook,

Bebo or other network sites.

9) Yazino founder Hussein Chahine said, "Communication is constantly evolving. Some people are as

used to seeing their friends' online image as they are their face."

10) "We are now just as likely to SMS or email a friend as we are to call them."

11) "People increasingly prefer quick and frequent engagement with instant updates on news than a

prolonged chat and are also finding new ways to catch up with friends from their comfort of their sofa."

12) More than seven in ten text their friends and family and 31 percent use social networking sites

while just 27 percent now use email as their primary means of contact.

13) A further 18 percent use live chat and instant messaging systems.

1. What is the title of the passage? (no more than 10 words)

_____________________________________________________________________________

2. Complete the following statement with proper words. (no more than 4 words)

   Some people see their friends' online image so often that they feel as if                .

3. Please fill in the blank in the fourth paragraph with proper words or phrases to complete the

sentence. (no more than 8 words)

___________________________________________________________________________

4. List two reasons why many people don't want to talk to people in person. (no more than 15 words)

____________________________________________________________________________  

5. What does the underlined word "These" (Line 1, Paragraph 3) probably refer to? (no more

than 10 words)

____________________________________________________________________________

多项选择题