问题 选择题

已知W、X、Y、Z为短周期元素,它们的原子半径依次增大,W与Z、X和Y分别同主族,Y、Z同周期。Z能与X形成两种常见的离子化合物,离子个数比均为2:1。下列说法错误的是

A.Y、Z、X、W的原子序数依次减小

B.W与X可形成既含极性共价键又含非极性共价键的化合物

C.由W、X、Y、Z四种元素组成的常见化合物一定显酸性

D.X的简单氢化物的沸点低于Y的简单氢化物的沸点

答案

答案:D

题目分析:Z能与X形成两种常见的离子化合物,离子个数比均为2:1,在短周期元素中应该是Na和O。X的原子半径小于Z的,则X是O,Z是Na。W与Z、X和Y分别同主族,Y、Z同周期,所以Y是S,W的原子半径最小,因此W是H。

A、S、Na、O、H的原子序数依次减小,A正确;

B、H和O生成的H2O2中既含极性共价键又含非极性共价键,B正确;

C、由四种元素形成的化合物是NaHSO4或NaHSO3,其溶液均显酸性,C正确;

D、水分子间存在氢键,所以H2O的沸点高于H2S的沸点,D不正确,答案选D。

单项选择题
单项选择题

Almost everyone agrees that America’s health-care system has the incentives all wrong. Under the present system, doctors and hospitals get paid for doing more, even if added tests, operations and procedures have little chance of improving patients’ health. So what happens when someone proposes that we alter the incentives to reward better care, not more care Well, Rep. Paul Ryan and Republicans found out. No surprise: Democrats slammed them for "ending Medicare as we know it. "

This predictably partisan reaction preying upon the anxieties of retirees—must depress anyone who cares about the country’s future. It is only a slight exaggeration to say that unless we end Medicare "as we know it," America "as we know it" will end. Spiraling health spending is the crux of our federal budget problem. In 1965—the year Congress created Medicare and Medicaid—health spending was 2.6 percent of the budget. In 2010, it was 26.5 percent. The Obama administration estimates it will be 30.3 percent in 2016. By contrast, defense spending is about 20 percent; scientific research and development is 4 percent.

Uncontrolled health spending isn’t simply crowding out other government programs; it’s also dampening overall living standards. Health economists Michael Chernew, Richard Hirth and David Cutler recently reported that higher health costs consumed 35.7 percent of the increase in per capita income from 1999 to 2007. They also project that, under reasonable assumptions, it could absorb half or more of the gain between now and 2083.

Ryan proposes to change that. Beginning in 2022, new (not existing) Medicare beneficiaries would receive a voucher, valued initially at about $ 8,000. The theory is simple. Suddenly empowered, Medicare beneficiaries would shop for lowest-cost, highest-quality insurance plans providing a required package of benefits. The health-care delivery system would be forced to restructure by reducing costs and improving quality. Doctors, hospitals and clinics would form networks; there would be more "coordination" of care, helped by more investment in information technology; better use of deductibles and co-payments would reduce unnecessary trips to doctors’ offices or clinics.

It’s shock therapy. Would it work No one knows, but two things are clear. First, as Medicare goes, so goes the entire health-care system. Medicare is the nation’s largest insurance program, with 48 million recipients and spending last year of $ 520 billion. Second, few doubt that today’s health-care system has much waste: medical care that does no good.

Under Ryan’s plan, incentives would shift. Medicare would no longer be an open ATM; the vouchers would limit total spending. Providers would face pressures to do more with less; there would certainly be charges that essential care was being denied. The Obama administration argues that better results can be achieved by modifying incentives within the existing system. Perhaps. But history suggests skepticism. It’s Ryan’s radicalism vs. President Obama’s remedy policy. Which is realistic and which is wishful thinking Burdened by runaway spending, Medicare "as we know it" is going to end. The only questions are when and on whose terms.

Which of the following areas is not seriously affected by budget on health care()

A.National defense

B. Scientific research

C. Better health care for retirees

D. People’s living standards