经济过热时，为抑制通货膨胀，央行可以（） A.降低再贷款利率 B.在公开市场购买国债

请从所给的四个选项中，选择最合适的一个填入问号处，使之呈现一定的规律性（）

A．A

B．B

C．C

D．D

螺线管通电后，吸引软铁a使弹簧伸长，如图所示，当滑动变阻器的滑片P向右移动时：（　　） A．弹簧长度增加，安培表读数变大 B．弹簧长度增加，安培表读数变小 C．弹簧长度减小，安培表读数变小 D．弹簧长度减小，安培表读数变大

《中国药典》2010年版采用水解后重氮化-偶合反应显红色进行鉴别的药物是（）

A.盐酸普鲁卡因

B.对乙酰氨基酚

C.盐酸利多卡因

D.阿司匹林

E.肾上腺素

创立元素周期表的科学家是（）。

A.门捷列夫

B.波义耳

C.居里夫人

D.玻尔

Crash-Prone The Solution Could Be Windows XP;
But does It Make Sense to Upgrade Your Operating System

You can hardly turn on the television or click on a Web page without seeing a colorful ad for Microsoft’s new Windows XP operating system, which launched on Oct. 25.
So, now that the long-awaited XP is here, what are you going to do about it Should you upgrade, and if you do, how hard is it and what are the potential drawbacks The decision is pretty easy if you really need a whole new Windows PC. They all come with XP preloaded, and in my tests of a few such models, they seemed to work well. I’m writing this on my own new personal computer, a Dell that came preloaded with Windows XP, and it worked great right out of the box.
The only downside is that if you’re keeping older printers, scanners and other peripherals, you may have to download new "drivers" — the small programs that allow a PC and a peripheral to interact. XP contains many of the drivers for recent-model printers and the like, sparing you from even digging out the disks that came with them. But if you have older equipment, you may have to download new drivers, because the original software that came with the hardware might not work with Windows XP.
It’s harder to decide what to do about XP if you have a PC that doesn’t need replacing. If you’re happy with the way things are working, don’t upgrade. It’s never a trivial thing to change operating systems, and you shouldn’t do it without a reason.
However, there are two big limitations in prior versions of Windows that XP does fix, and that might make an upgrade worthwhile. These are stability — that is, the ability not to crash, or at least to do so rarely — and compatibility. Windows 98 and Windows ME, the previous consumer versions, had wide compatibility with consumer software and peripherals, but lousy stability. Windows 2000, the prior business version, had great stability, but limited compatibility with consumer software and add-on hardware.
Windows XP is designed to combine the stability of Windows 2000 (with which it shares underlying code) with the compatibility of Windows 98 and Windows ME, and in my experience, it does a good job at that. So if you need more reliability or compatibility than your current version of Windows supplies, an upgrade may be in order.
But there’s a catch. Microsoft says that an XP upgrade will really be sensible only if your PC is two years old or less — built after 1999. And you need at least a 300MHz processor and 128 megabytes of memory, though I recommend at least 192MB, and 256MB is even better. Also, you’ll need a roomy hard disk — Windows XP alone will suck up 1.5 gigabytes.
So there are only a limited number of PCs for which upgrading makes sense, and you may have to invest in beefing yours up first.
Not only that, but you must have Windows 98, Windows ME or Windows 2000 on your current system to upgrade. If you have Windows 95 and somehow still have a new enough machine to qualify, you have to buy a very expensive, "full" version of Windows XP, basically wipe out your whole hard disk and start from scratch with XP, losing all your installed programs and settings.
If you’re good to go, you next have to decide which upgrade version of XP is right for you — the $99 Home Edition or the $199 Professional. The differences between them are surprisingly small, and 95 percent of home and small-business users will be fine with the home version. Buy the pro version only if you are running more than a modest network or need special security features.
Note that if you have Windows 2000, or NT 4.0, you can upgrade only to Windows XP Professional, not the Home Edition. If you have Windows 98 or ME, you can choose either flavor of XP.
In my tests, which included five PCs running all the main older versions; the Windows XP upgrades, both home and pro, went very smoothly.
The process took about an hour in each case, and the installation software was friendly and clear in its instructions and progress reports.

Windows XP Home Edition is appropriate for ______.
A. all the main older versions of Windows
B. Windows 98 or ME
C. Windows 2000
D. NT4.0