问题 单项选择题

在多媒体的音频处理中,由于人所敏感的音频最高为 (14) 赫兹(Hz),因此,数字音频文件中对音频的采样频率为 (15) 赫兹(Hz)。对一个双声道的立体声,保持一秒钟声音,其波形文件所需的字节数为 (16) ,这里假设每个采样点的量化位数为8位。

MIDI文件是最常用的数字音频文件之一,MIDI是一种 (17) ,它是该领域国际上的一个 (18)

(18)处填()。

A.控制方式

B.管理规范

C.通信标准

D.输入格式

答案

参考答案:C

解析:

[分析]: 人的听觉带宽一般为20Hz~20kHz,人敏感的音频最高为22kHz。数字音频文件中对音频的采样频率为44.1kHz。

声音能按波形声音采样、存储和再现,如果不经过压缩,声音数字化后每秒所需的存储量可按下式估算:

文件的字节数=采样频率×采样位数×声道数÷8

因此,题目所要求的存储量为1×44100×8×2+8=88200字节。

MIDI是一种乐器数字接口的英文缩写,泛指数字音乐的国际标准。

完形填空

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项,并在答题卡上将该项涂黑。选项中有两项为多余选项。

After entering high school, you must wonder how to study well. Here are some good skills for you.

Go to class.

If you want to do well at school, going to class is the first step in studying well. If you miss classes, you will miss what the teacher thinks is important; as a result, you’ll miss what is the most likely to end up on the test.    小题1: 

Take good notes.

Try not to write down everything.  小题2: Write down unfamiliar terms. After class, review your notes as soon as possible. You can fill in details that you missed and review the material while it is still fresh on your mind.

 小题3: 

If you are struggling in class, talk to your teacher. He or she may be able to give you more help or tutor you before or after class. Most teachers have little sympathy(同情) for students who just become worried about failing during the last few weeks of the grading period.

Take part in class discussions.

In order to learn more in class, it is helpful to take part in class discussions. Asking questions and having eye contact with your teachers and classmates can increase your participation(参与)and your focus during the class discussion.   小题4: This helps you make your point clear in class.

Form study groups.

 小题5:  Make sure that everyone is familiar with the material because you do not want to spend time re-teaching material to people who do not understand it. Be careful! Sometimes group sessions can become chatting sessions.

A.Don’t be late for your class.

B.Talk to your teacher if you need help.

C.You should write down all the new terms.

D.So if you want to study well, go to every class.E. Get students together who want to do well in class.

F. All you need is to put the main points in your own words.

G. If the material is difficult, you’d better read it before class.

单项选择题