下面对再生产理解不正确的一项是（）。 A.按规模分为简单再生产和扩大再生产 B.简单

The simple act of surrendering a telephone number to a store clerk may seem innocuous—so much so that many consumers do it with no questions asked. Yet that one action can set in motion a cascade of silent events, as that data point is acquired, analyzed, categorized, stored and sold over and over again. Future attacks on your privacy may come from anywhere, from anyone with money to purchase that phone number you surrendered. If you doubt the multiplier effect, consider your e-mail inbox. If it’s loaded with spam, it’s undoubtedly because at some point in time you unknowingly surrendered your e-mail to the wrong Web site.

Do you think your telephone number or address are handled differently A cottage industry of small companies with names you’ve probably never heard of—like Acxiom or Merlin—buy and sell your personal information the way other commodities like corn or cattle futures are bartered. You may think your cell phone is unlisted, but if you’ve ever ordered a pizza, it might not be. Merlin is one of many commercial data brokers that advertises sale of unlisted phone numbers compiled from various sources—including pizza delivery companies. These unintended, unpredictable consequences that flow from simple actions make privacy issues difficult to grasp, and grapple with.

In a larger sense, privacy also is often cast as a tale of "Big Brother"—the government is watching you or a big corporation is watching you. But privacy issues don’t necessarily involve large faceless institutions: A spouse takes a casual glance at her husband’s Blackberry, a co-worker looks at e-mail over your shoulder or a friend glances at a cell phone text message from the next seat on the bus. While very little of this is news to anyone—people are now well aware there are video cameras and Internet cookies everywhere—there is abundant evidence that people live their lives ignorant of the monitoring, assuming a mythical level of privacy. People write e-mails and type instant messages they never expect anyone to see. Just ask Mark Foley or even Bill Gates, whose e-mails were a cornerstone of the Justice Department’s antitrust case against Microsoft.

And polls and studies have repeatedly shown that Americans are indifferent to privacy concerns. The general defense for such indifference is summed up a single phrase: "I have nothing to hide. " If you have nothing to hide, why shouldn’t the government be able to peek at your phone records, your wife see your e-mail or a company send you junk mail It’s a powerful argument, one that privacy advocates spend considerable time discussing and strategizing over.

It is hard to deny, however, that people behave different when they’re being watched. And it is also impossible to deny that Americans are now being watched more than at any time in history.

Companies like Acxiom or Merlin（）

A. make a profit by acquiring and selling personal information

B. compile telephone directories for local business transaction

C.are law firms specializing in dealing with privacy issues

D. are agencies whose major mission is to protect privacy

在Rt△ABC中，∠C=90°，∠A=30°，则sinB=______，tanA=______．

下列说法正确的是（　　）

A．导体在磁场中运动能产生感应电流

B．电动机是消耗了机械能得到电能

C．发电机将贮存的化学能转化成电能

D．换向器能改变线圈中的电流方向

急性炎症性脱髓鞘性多发性神经病典型的脑脊液改变（）

A.蛋白-细胞分离

B.细胞-蛋白分离

C.细胞、蛋白均增高

D.细胞、蛋白均不增高

E.白细胞增高

眼压高低主要取决于房水循环中的哪些因素（）

A.睫状突生成房水的速率

B.葡萄膜巩膜通道的大小

C.上巩膜静脉压

D.前房角的宽窄

E.房水通过小梁网流出的阻力