小草偷偷地从土地里钻出来，嫩嫩的，绿绿的。园子里，田野里，瞧去，一大片一大片满是的。坐着，躺着，打两个滚，踢几脚球，赛几趟跑，捉几回迷藏。风轻悄悄的，草软绵绵的。
      桃树，杏树，梨树，你不让我，我不让你，都开满了花赶趟儿。红的像火，粉的像霞，白的像雪。花里带着甜味；闭了眼，树上仿佛已经满是桃儿，杏儿，梨儿。花下成千成百的蜜蜂嗡嗡地闹着，大小的蝴蝶飞来飞去。野花遍地是：杂样儿，有名字的，没名字的，散在草丛里像眼睛像星星，还眨呀眨的。
      “    ▲    ”，不错的，像母亲的手抚摸着你，风里带着些新翻的泥土的气息，混着青草味儿，还有各种花的香，都在微微润湿的空气里酝酿。鸟儿将巢安在繁花嫩叶当中，高兴起来了，呼朋引伴的卖弄清脆的歌喉，唱出宛转的曲子，跟轻风流水应和着。牛背上牧童的短笛，这时候也成天嘹亮的响着。

      If you want to be a better reader，what should you know about the speed(速度)of reading? Some people read very quickly，when others read very slowly. But which one is better? The quick reader may be a good reader when he reads a story-book for fun. But he may not be able to slow down to read instructions(说明书) carefully. The slow reader may be a good reader. But he may spend too much time reading a story for fun. So the reader who reads everything quickly or the one who reads everything slowly isn't really a good reader. Here are four things to remember about the speed of reading.
       Knowing why you are reading will help you to know whether(是否) to read quickly or slowly.
Some things should be read slowly throughout. Examples(例子)are instructions for making or doing something. Math books，science and story-books are full of important information. You must read these things slowly to understand and remember every important idea.
     Some things should be read quickly throughout. Examples are stories for enjoyment，letters from friends，and some news from newspapers.
In some of your reading，you must change your speed from fast to slow and slow to fast. You will need to read some pages quickly and then slow down and do more careful reading when you come to important ideas.

在收音机等电器中，有一个叫电位器的变阻器．电位器的外形及其内部构造如图所示．图中A、B、C三个焊接点相当于变阻器的三个接线柱．使用电位器时，下列说法正确的是（　　）

如图所示，小明在艺术节上用吉他弹奏优美的乐曲．对于吉他发出的声音，下列说法正确的是（　　）

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