问题 单项选择题

操作系统的作用是()

A.将源程序编译成目标程序

B.负责诊断机器的故障

C.负责外设与主机之间的信息交换

D.控制和管理计算机系统的硬件和软件资源

答案

参考答案:D

填空题
单项选择题

By almost every measure, Paul Pfingst is an unsentimental prosecutor. Last week the San Diego County district attorney said he fully intends to try (1) Charles Andrew Williams, 15, as an adult (2) the Santana High School shootings. Even before the (3) Pfingst had stood behind the controversial California law that (4) treating murder suspects as young as 14 as adults.

So nobody would have wagered that Pfingst would also be the first D. A. ( district attorney) in the U. S. to (5) his very own Innocence Project. Yet last June, Pfingst told his attorneys to go back over old murder and rape (6) and see ff any unravel with newly developed DNA-testing tools. In other words, he wanted to revisit past victories—this time playing for the other team. "I think people misunderstand being conservative (7) being biased," says Pfingst. "I consider myself a pragmatic guy, and I have no interest in putting (8) people in jail."

Around the U. S. , flabbergasted defense attorneys and their jailed clients cheered his move. Among prosecutors, (9) , there was an awkward pause. (10) , each DNA test costs as much as $ 5,000. Then there’s the (11) risk: if dozens of innocents (12 , the D.A. will have indicted his shop.

(13) nine months later, no budgets have been busted or prosecutors ousted. Only the rare case merits review. Pfingst’s team considers convictions before 1993, when the city started (14) DNA testing. They discard cases if the defendant has been released. Of the 560 (15) files, they have re-examined 200, looking for cases with biological evidence and defendants who still (16) innocence.

They have identified three so far. The most compelling involves a man (17) 12 years for molesting a girl who was playing in his apartment. But others were there at the time. Police found a small drop of saliva on the (18) shirt—too small a (19) to test in 1991. Today that spot could free a man. Test results are due any day. (20) by San Diego, 10 other counties in the U.S. are starting DNA audits.

17()

A.observing

B.serving

C.sentencing

D.inhabiting