问题
填空题
噪声的发声体做______振动时发出的声音.如图所示,甲和乙是两种声音的波形图,其中______图是噪声的波形.

答案
从物理学角度看,噪声是指发声体做无规则振动时发出的声音,对比甲与乙,不难看出:甲波形很有规律,属于乐音;乙杂乱无章属于噪声.
故答案为:无规则;乙.
噪声的发声体做______振动时发出的声音.如图所示,甲和乙是两种声音的波形图,其中______图是噪声的波形.
从物理学角度看,噪声是指发声体做无规则振动时发出的声音,对比甲与乙,不难看出:甲波形很有规律,属于乐音;乙杂乱无章属于噪声.
故答案为:无规则;乙.
Choose the best response from A to F in the box according to the sentence given. Each choice should be used only once. | |
( )1. Do you mind if I smoke here? ( )2. I'm going to take an exam. ( )3. Dad, there's something wrong with your computer. ( )4. Could you lend me some books? ( )5. What about having a bottle of orange juice?
|