问题 单项选择题

允许多个程序同时进入内存并运行的是

A.程序并发执行

B.多道程序设计

C.程序的顺序执行

D.时间片轮转

答案

参考答案:B

解析:[命题目的] 本题主要考查了程序并发执行的相关知识。[解题要点] 程序并发执行是指两个或两个以上程序在计算机系统中处于已开始执行且尚未结束的状态。多道程序设计就是允许多个程序同时进入内存并运行。[错解分析] 多道程序设计的方法是允许多个程序同时进入内存并运行的,故B) 正确;而程序并发执行和此问题不相关,程序的顺序执行和时间片轮转都不允许多个程序同时进入内存并运行,故A) 、C) 、D) 选项错误。[考点链接] 掌握程序的顺序执行的特点,以及顺序执行和并发执行的区别。

单项选择题
单项选择题

For years Internet merchants have poured millions of dollars into new technologies to make their sites easier to use. So why aren’t online customers happier

Customer satisfaction levels have remained almost fiat through the last several years. The problem, according to Larry Freed, chief executive of a consulting and research firm called ForeSee Results, is not so much that consumers have ignored the many improvements made in recent years. Rather, be said, they still expect more from Internet shopping than it has delivered.

"If we walk into a local store, we don’t expect that experience to be better than it was a couple years ago," Mr. Freed said. "But we expect sites to be better. The bar goes up every year." In ForeSee’s latest survey, released last month, just five e-commerce sites registered scores higher than 80 out of 100, and no site scored higher than 85. It was much the same story a year ago, when just five scored higher than 80, with no site surpassing 85. "Scores have inched up over time for the best e-commerce companies, but the overall numbers haven’t moved drastically," Mr. Freed said. "At the same time though, if you don’t do anything you see your scores drop steadily."

That dynamic has been a challenge for online merchants and investors, who a decade ago envisioned. Internet stores as relatively inexpensive (and therefore extremely profitable) operations. Now some observers predict a future where online retailers will essentially adopt something like the QVC model, with sales staff pitching the site’s merchandise with polished video presentations, produced in a high-tech television studio.

QVC.com is evolving in that direction. The Web site, which sold more than $1 billion in merchandise in 2006, has for the last five years let visitors watch a live feed of the network’s broadcast. But in recent months, QVC.com has also given visitors the chance to watch archives of entire shows, and in the coming months visitors will be able to find more video segments from recent shows, featuring individual products that remain in stock. Bob Myers, senior vice president of QVC.com, said the Web site’s video salesmanship is especially effective when combined with detailed product information, customer reviews and multiple photographs.

About eight months ago, for instance, a customer said that she could not determine the size of a handbag from the photographs on the site because she could not tell the height of the model who was holding it. Within two weeks the site tested and introduced a new system, showing the bags with women of three different heights. The results were immediate: women who saw the new photographs bought the bags at least 10 percent more frequently than those who had not.

Still, Mr. Myers said, video is a critically important element to sales. "E-commerce started with television commerce," he said. "The sites who engage and entertain customers will be winning here in the near future." Such a prospect is not necessarily daunting to other e-commerce executives. Gordon Magee, head of Internet marketing for Drs. Foster & Smith, based in a Rhinelander, Wis., said a transition to video "will be seamless for us." The company, Mr. Magee said, has in recent weeks discussed putting some of its product on video "so customers could see a 360-degree view they don’t have to manipulate themselves.

Mr. Magee’s attitude towards using videos in E-commerce seems to be()

A. skeptical

B. critical

C. supportive

D. confused