问题 填空题

人类生活离不开水,为了在实践中了解水,某中学研究性学习小组对附近河流水质的状况进行相关的调查研究。

⑴取水样,静置后过滤。为了使悬浮物快速沉淀,常加入的一种试剂是        ;]

⑵若要检验废黄河水属于硬水还是软水,可用的物质是          

⑶若要测定废黄河水的酸碱度,可选择           

答案

(1) 明矾      (2) 肥皂水      (3) pH试纸

题目分析:为了使悬浮物快速沉淀,常加入净水剂明矾,明矾溶于水后,形成胶状物,吸附悬浮杂质而沉降;生活中常用肥皂水,通过观察肥皂水起泡的多少来检验硬水与软水;常用pH试纸来检验溶液的酸碱度。

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Dear Economist,

     My newlywedded wife and I are deeply in love. There is, however, one issue that threatens the

happiness of our marriage. I absolutely insist on shopping at Walmart. My  wife, meanwhile, would 

 rather  avoid Walmart at all costs. I have recently tried to convince her that not only does Walmart

offer the lowest prices known to man, but that the chain is also a force for good-lower prices mean

better standards of living for all consumers, increased global trade means a tighterknit(紧密团结的)

international community, and efficient operations translate into higher productivity growth for the

economy. My wife complains about poor labour policies, the fact that Walmart squeezes suppliers,

and that it puts local shops out of business.

     Who is right? Will our marriage survive?

     Brian Gee

     Dear Brian,

     I have to agree with you about Walmart. Jason Furman, then an economist at New York University,

now an adviser to President Obama, famously argued in 2005 that Walmart was unwittingly (不知不觉地) a  progressive success story.The chain's prices don't much affect me(I prefer Whole Foods)but

Furman estimated  that they benefited lowandmiddleincome Americans to  the sum of around $250

billion a year.

      Walmart does not pay much, so it may depress  wages.Then again, it may increase wages by

offering jobs to the otherwise-unemployed. Either way, the benefits of low prices to Walmart shoppers

far outweigh any seemingly reasonable costs to Walmart employees. And while it is true that Walmart

employees tend to be poor, the same is true of Walmart shoppers.

      Armed with this information you can face your wife with confidence. You are sure to win the

conversation. The divorce is likely to be more argued.

      Economist

1. What concerned Brian Gee so much that he wrote the letter?

A. His wife refuses to shop at Walmart.

B. They are faced with a divorce.

C. They  can't  afford  the  costs  of  shopping  at   Walmart.

D. They are in conflict about shopping at Walmart.

2. Brian Gee's wife tends to hold the opinion that________.

A. it is wrong for Walmart to depress its employees' wages

B. consumers' lives have improved thanks to Walmart

C. Walmart's business operation increased productivity in economy

D. Walmart's business increases global trade

3. What can be inferred from the reply letter?

A. Some employees accept the low pay to keep the job.

B. Walmart appeals to only poor consumers and poor employees.

C. Employees suffer from Walmart's low prices more than consumers.

D. Jason Furman, a New York University economist, spoke highly of Walmart.

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