题干

下面是某学生在课外做“比较材料的隔声性能”活动时记录的一些内容:

【器材】:一个能发声的电子铃,一个鞋盒,待比较的材料(棉布、报纸、塑料布、泡沫塑料及其它材料)、一把长卷尺.

【步骤】:小明先将衣服包好电子铃,放入盒内,让其发声.再安排一位同学远离盒子直到听不到铃声时为止,用卷尺测出同学到盒子的距离.换用其它材料完成上述步骤.

【提问】:①小明是通过____ 来比较材料隔声性能的.这种方法叫____ .

②小芳认为:比较的时候,远离的方向要相同,因为风向不同会影响声音的传播(这种方法叫控制变量法).请你想一想,还要保持哪些因素相同呢?写出两个:____ 、____ .

上一题 下一题 0.0难度 选择题 更新时间:2017-07-26 06:50:28

答案(点此获取答案解析)

①比较声源到听者的距离,转换法,电铃的方向,电铃的响度

同类题2

阅读理解

    Anki has introduced Cozmo, a little robot powered by an advanced artificial intelligence. Cozmo promises to be for more interactive(互动的)than any toy robot.

    Cozmo, which can lie in your hand, has a “brain”---technically its CPU---that can process data amazingly fast. In addition, Cozmo has a playful personality. He's designed to react to emotions and even ask users to play with him.

    Cozmo is not the first interactive toy to reach the market nor is it the first robot toy. What sets Cozmo apart from the other “smart toys” is that it has greater play value than those toys, which can become repetitious all too quickly.

    “Every interaction with Cozmo is different, so you do not put up with repetitive play patterns and responses typically found with other preprogrammed robots,” explained Anki spokesperson Peter Nguyen. Because it has functionality that is similar to that of video games, Cozmo also can receive regular updates, which could extend its playability. Still, Anki has designed this toy to be just that: a toy. It's not an advanced computerized robot. Its software is app-based.

    Cozmo lacks the “traditional” human-like robot form factor(要素)of legs, arms, and a head. But Cozmo does have an OLED screen/face with blue eyes, which in fact were designed to help it connect with its user.

    “I'm glad my kids are already raised,” said Roger L. Kay, analyst at Endpoint Technologies Associates. “Otherwise, they might become more antisocial if their relationship with Cozmo is more satisfying than those with real people,” said Kay. “Cozmo might encourage kids to learn more about technology or even inspire them to try programming and similar studies,” said Charles King, analyst at Pund-IT.

    Yet this technology does promise to be more than a toy. “It's a pretty cool invention and might have further applications, for example in elder care,” suggested Kay.