In 2007 it was the 25th [----1----] for the CD, also known as the compact disc. In 25 years CDs have become ubiquitous, to the point where we take them completely for granted. But inside a CD you find an amazing amount of technology.

To understand just how profound the effect of the CD has been, it is helpful to [----2----] at the two reigning technologies in the early 1980s: the vinyl LP and the compact cassette. You may recall just how bizarre the vinyl LP was. An aficionado would have a massive turntable with little black and white markings along the edge to calibrate the speed of the turntable with a strobe light. The turntable rested on big vibration- dampening pads to try to keep any spurious vibrations away from the turntable. The tip of the tone arm was measured with a sensitive scale to minimize its pressure in the record’s groove. The LP itself was sprayed with an anti-static gun to cut back on dust. And even with all this technology, the first thing you heard from any vinyl disk was hiss. With the cassette the story was the same: the tape stretched, it flaked, it broke, it jammed.

Enter the compact disc. Because of its digital nature, its sound quality was amazing compared to vinyl or tape. It also eliminated hiss once and for all. Things like dust, [----3----] and small scratches didn’t matter. The sound did not degrade over time as it did with vinyl or tape. And normal heat levels, as in a locked car on a hot summer day, didn’t cause any problems. And there was an added [----4----]-over time; compact discs became incredibly inexpensive to produce.

Vocabulary Focus

Take (something) for granted (v phr) to not appreciate or show that you are grateful for how much you benefit from something
Aficionado (n) someone who is very interested in and enthusiastic about a particular subject
Vibration (n) the act of shaking slightly and quickly, in a way that is felt rather than seen
The story was the same (idiom) a situation that is similar to a previous one

Specialized terms

Strobe light (a phr) a light that quickly flashes on and off

Exercises for Today:

听写&翻译练习：（奖励50HY）
a) 听写填空：补全课文中的空白处。
b) 翻译：翻译文本中高亮的句子（注意联系上下文哦）
讨论问题：（奖励100HY~200HY）
今日话题讨论点击进入
c) New：每日Skit听写：奖励50HY ~ 250HY（猫头鹰听力剧院改版中！更多奖励活动哦~）点击进入

说明：

1.本栏目由空中英语教室授权沪江网制作.
2.更新频率：周一至周六。
3."讨论"话题全新改版至小组讨论，奖励升级，凡参与者奖励100HY，积极参与者奖励200HY。
4.参考答案、译文及课文讲解音频回复可见。
5.课文音频下载

6.多重参与方式：1)小组讨论 2)节目订阅 3)Skype每日在线语音讨论

7.Skype每日在线语音讨论特别说明：彭蒙惠语音讨论群详细图解说明
安装skype后，加每日语音主持人xy_chouchou@163.com和dantekung@gmail.com
时间: 周一至周六, 周日Free Talk 19:00-20:00
内容: 对课文词汇和文章进行讨论

已经奖励 alanruan,bigpig521,chen_wenyu,chenli423,cherrxiao,cheyenne_00,choki,corner001,elsa_ly,faith861022,gujf0725,HarryPP,ilovehere,jason1005,JerryHao,jhwang0905,jiroleng,kathyhao,klmt,lael01,lee_ting,lemonzly,littleRita,mmbee,rrose,sagi_longyu,shelly_lcy,SoniaTang,susugrace,tryhjbl,wlzmwq,wwj-rachel,xcdd,xfqin,xinxinghome,ziyunisabell,zzz403,小闸蟹,扬4ever
单个用户操作：金钱50 经验20 魅力20