问题 问答题

被誉为“亚洲第一井”的科学钻井工程,在连云港市东海县毛北村进行.这是一口设计直径为156mm、深5000m,用于地下科学研究的深井.若在工程进行中测量钻井深度,从井口向下发射平均速度为340m/s的超声波,20s后接收到回波信号,则井的实际深度为多少?

答案

根据题意20s钟是声音来回传播的时间,那么声音从井口传递到井底的时间为

1
2
×20s=10s;

根据速度公式得:s=vt=340m/s×10s=3400m.

即井的实际深度为3400m.

答:井的实际深度为3400m.

问答题

很多化学反应是没有明显的实验现象的,如一些酸碱的,中和反应,但是聪明的人们发现了酚酞、石蕊等指示剂,通过指示剂颜色的变化可以证明化学反应是否发生,或是否恰好反应.张南同学想探究哪些物质能做酸和氢氧化钠溶液反应的指示剂.

一、[提出问题]是否可以用其他试剂证明酸与氢氧化钠溶液能发生化学反应.

二、[进行实验]甲、乙、丙三位同学进行如下实验.

实验分组    实验步骤及现象    结  论
  甲同学的实验取_定量氢氧化钠溶液加入试管中.向其中滴加

稀盐酸,无明显现象,再滴加几滴氯化铁溶液时看不到红褐色沉淀.

用氯化铁溶液可以证明稀盐酸与氢氧化钠溶液能发生化学反应.
  乙同学的实验取一定量氢氧化钠溶液加入试管中,向其中滴加稀盐酸,无明显现象,再滴加几滴硫酸铜溶液时看到蓝色沉淀.用硫酸铜溶液不能证明稀盐酸与氢氧化钠溶液能发生化学反应.
  丙同学的实验取一定量稀硫酸加入试管中,滴加氢氧化钠溶

液,无明显现象,再滴加几滴氯化钡溶液时出现白色沉淀.

用氯化钡溶液可以证明稀硫酸与氢氧化钠溶液能发生化学反应.
[交流评价]请你评价三位同学由实验现象获得的结论是否正确,并说明理由.

正确或错误    理    由
甲同学
乙同学
丙同学
四、[归纳总结]

①证明化学反应是否发生,可以从两方面考虑:一方面是验证是否有新物质生成;另一方面是

______

②在验证实验过程中还要考虑反应物______.

阅读理解

Most people who experience bad service while traveling, shopping, or dining out do no complain. They accept bad services or products without making a sound. Why? Many feel complaining won’t do any good. In fact, they’re wrong, because companies don’t want their customers unhappy. Not sure you can do it? Here are some ways to use when things go wrong.

1.If you have a complaint, do something about it right away. The longer you wait, the harder it will be to get your complaint solved.

2.First, complain to the servers. If they are not going to solve your problem, then ask politely to speak to a manager. And if that doesn’t work, you can always request to speak to the manager’s manager!

3.Demand a discount(折扣). Let’s say you were promised a hotel room with an ocean view, but got a view of a brick wall instead; if you were promised a seat in the front of a plane, but got a seat in the back. You should do something about both of these situations. Ask a special discount.

4.Don’t be passive. Offer ways you think the company can satisfy you.

5.Insist on the price you were told. If you are refused, get a manager’s name and telephone number, and promise to follow up with a letter and a telephone call.

6.If all else fails, wait until you get home and take action. Call the company’s head office, and speak to the most powerful person possible. Then follow up your call with a letter of complaint. If necessary, call the customer protection office in your city and complain.

小题1:

According to the text, people don’t complain because________.

A.they think complaining doesn’t work

B.they consider it wrong to complain

C.they don’t want to waste their time

D.they don’t want to become unpopular小题2:

To complain about something, you should________.

A.wait until you come back home

B.prepare for a long time

C.talk to the manager directly

D.try to solve the problem actively小题3:

What might be the best title for the text?

A.Get what you should get

B.Complain as you please

C.Take action to deal with problems

D.Avoid trouble and don’t complain