问题 单项选择题

下面关于PC机数字声音的叙述中,正确的是【 】。

A.语音信号进行数字化时,每秒产生的数据量大约是64KB(千字节)

B.PC机中的数字声音,指的就是对声音的波形信号数字化后得到的"波形声音"

C.波形声音的数据量较大,一般需要进行压缩编号

D.MIDI是一种特殊的波形声音

答案

参考答案:C

解析:本题是考查数字声音的基本知识。语音信号的取样频率一般为8KHZ,因此一秒产生的数据量是8K比特,也就是1K字节,因此A不正确。PC机中的数字声音有两种表示方法,一种是通过对实际声音的波形信号进行数字化获得的“波形声音”,另一种是通过符号对声音进行描述,然后再合成的“合成声音”,因此B也不对。MIDI是数字乐器与计算机的接口,不是波形声音,D错了。通过压缩编码,可以使波形声音的数据量变小,因此选C。

填空题



For more than two centuries, American’s colleges and universities have been the backbone of the country’s progress. They have educated the technical, managerial, (1) and provided generation after generation of national leaders. Today educators from around the globe are turning to U. S. institutions of higher learning (2) . They are apt to find many reasons for the excellence of American universities, but (3) stand out as watersheds:
Education (4) : In 1862 Congress enacted the Land-Grant College Act, which essentially extended the opportunity of higher education (5) , including such disenfranchised groups as women and minorities. Each state was permitted to sell large tracts of (6) and use the proceeds to endow at least one public college.
(7) : Over the years, the decentralization and diversity of the America’s colleges and universities have promoted competition for students and resources. Competitive pressure first arose (8) . The academy’s impact really grew after World War II, when (9) commissioned by President Roosevelt argued that it was the federal government’s responsibility to (10) for basic research. Instead of being centralized in government laboratories, scientific research (11) in American universities and generated increasing investment. It also gave graduate students research opportunities and helped (12) far and wide, to the benefit of industry, medicine and society as a whole.
(13) : The end of the World War II saw passage of the Servicemen’s Readjustment Act of 1944. The law, which provided for (14) for returning veterans, made an already democratic higher-education system accessible in ways that were (15) in Europe, opening the doors of the best universities to men and women who had (16) of going to college.
(17) : The creation of federal loan guarantees and subsidy programs, as well as outright grants for college students brought (18) to higher education and further helped to democratize access. Since its founding (19) , the Federal Family Education Loan Program has funded more than 74 million student loans worth more than (20) .

单项选择题