四级阅读理解精练及答案

　　In time, 64 -bit PCs could change the face of desktop computing. A 64 -bit chip can run longer,more complex instructions than a 32 -bit one, improving performance of dataintensive tasks suchas audio and video encoding, advanced engineering design apps1 ,and, naturally, games.

　　Equally key is a 64-bit CPU's ability to recognize and use a lot more RAM2 . Today's 32 -bit chips,such as AMD's Athlon XP and Intel's Pentium 4 , can address up to 4GB of RAM split between theOS and applications. Few PCs have that much memory, and even fewer apps use it. But with ever-more-complex software, that limitation may become a bottleneck, making Athlon 64's ability toaddress a whopping terabyte ( 1000GB) 3 of physical memory very attractive.

　　Why is AMD pushing the 64 -bit angle at all? Because company executives believe the 64 -bitdesktop age is dawning now."Once video editors watch a 64-bit PC encode video directly to a DVDon the fly, they'll want one , "says Rich Heye , vice president of AMD's microprocessor unit. Andonce gamers see the cinematic quality that 64-bit chips help make possible , they'll want one.Though mass-market adoption will take a few years, " the average lifetime of a PC is three to fouryears, and I think a lot of people will be running 64 bits before that's up, "Heye says.

　　Executives at Intel disagree, seeing 64-bit computing as largely a server technology in the shortterm."With just 5 percent of servers using 64-bit addressability, there is little need today [ for 64bits] on the desktop, "says George Alfs, Intel spokesperson, adding that with out software andother tools to make it work at its best, 64 bits doesn't mean much.

　　MicroDesign Resources's Krewell sees Intel's resistance to 64 bits for the desktop as a move toprotect its sizeable investment in its 64-bit Itanium CPU, designed for servers and workstations.

　　Meanwhile, with Athlon 64 , AMD has reignited the chip wars."That's always good news for users, "says MDR's Krewell.

　　练习题：

　　Ⅰ. Choose the word which has the same or similar meaning with the underlined word:

　　1. AMD's release of its Athlon 64 chips

　　A. launch B. set free

　　2. more complex instructions than a 32 -bit one

　　A. not simple B. not clever

　　3. Because company executives believe

　　A. workers B. managers

　　4. to protect its sizeable investment

　　A. rough B. huge

　　5. desktop age is dawning now

　　A. returning B. coming

　　Ⅱ. Question :

　　Where were 64-bit CPUs used before?