问题 名词解释

带宽

答案

参考答案:

带宽即频带宽度,是一个度量频率范围或频谱宽度的参数,它用单一数值来表示,该单一数值等于两个界限频率之差。

“带宽”用于信道,可称信道带宽,表征通信信道容量参数之一,信道带宽影响信道传输信息的速率。

在模拟通信系统中,带宽用赫兹(Hz)作单位来表示。例如典型的模拟电话信道的有效带宽为3100Hz;在数字通信系统中,带宽除了用赫兹(Hz)作单位来表示外,还用相应的传输速率比特/秒(bit/s)作单位来表示。

单项选择题

Text 3

It is because of his plays that Shakespeare is now considered the greatest English writer in history. The era in which he lived, Elizabethan England, was a time in which broad interests and creativity could flourish. Elizabeth, the queen, was beloved by her subjects and proved to be a powerful and able ruler. Under the reign of Elizabeth, England changed from an island kingdom to an expanding empire. England grew rich through trade. Sixteenth-century Englishmen traveled to the New World and to Africa. Music, dance, poetry, painting, and architecture flourished; but the art form in which Elizabethan England distinguished the rest of Europe was the theater.

The theater, which had practically disappeared from Europe was, at this time, received as a part of the church service. Later, no longer as a part of the service, the" mystery plays" responded to popular taste by adding more and more comic elements. In England, they were sponsored by various trade guilds and presented on stage wagons that went from place to place. When the mystery plays began to lose their appeal, they were replaced by "morality" plays which always taught a moral.

In Renaissance England, writers were particularly interested in classical texts such as Latin and Greek plays. Schools and universities began to produce comedies and tragedies by Platus, Terence, and Seneca. Shakespeare was well acquainted with classical humanities and classical tragedies and comedies often served as models in his own drama. A Renaissance man, Shakespeare’s interest went beyond book learning to practical knowledge of military strategy, seafaring, business affairs, and the new geographical discoveries, all evident in his plays.

Companies of strolling plays which had specialized in morality plays responded to the change by staging new plays. Professional actors, who had been viewed by English society as little better than vagrants or criminals, gradually came under the protection of the nobility. Licensed theater companies were formed; Shakespeare belonged to one of those, where in addition to his writing, he acquired a wide experience in acting and theater management.

The theater grew in popularity and public theaters were built, not inside the city limits but just outside, along with other places of entertainment. Theaters in Elizabethan England were patronized by all social classes. The Globe Theater, built in 1599, where many of Shakespeare’s plays were performed, had a platform stage jutting out into a central courtyard. The audience stay around three sides of this platform the lower-class who each paid a penny in the pit and the wealthier spectators in the galleries above. The orchestra was on stage, as music was usually a significant part of the production. Indeed, the costumes, scenery, singing, playing, and dancing, as well as acting was essential to the total show. There was no lighting, however, plays were performed in the afternoon. Shakespeare knew his audience: his theater is addressed not just to the educated but to all classes of society.

According to the text ,the theater()

A.first appeared in England.

B.follows two classical rules.

C.were only sponsored by the nobility.

D.had various types.

单项选择题