题干

在亚丁湾海域,我国海军护航编队使用“金嗓子”(又名“声波炮”)震慑海盗.它的声波定向发射器外观类似喇叭,能发出145dB以上的高频声波,甚至比喷气式飞机引擎的噪声还要刺耳,根据以上信息,下列说法中错误的是(  )

A:“金嗓子”发出的声波是超声波

B:声波定向发射器喇叭状外观可以减少声音的分散,从而增大响度

C:声波具有能量

D:使用“金嗓子”时,护航官兵佩戴耳罩是在人耳处减弱噪声

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A

同类题3

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    That night, Sue quarreled with her mother, and she ran out of the house. Since she left in a hurry, she didn't take any money with her.

    When she passed a noodle shop, she suddenly felt very hungry. She wished for a bowl of noodles, but she had no money. The owner saw her standing outside and asked her if she would like a bowl of noodle. She nodded but then she said that she didn't have any money.

    “Okay, I'll treat you.” the owner said. A few minutes later, the owner brought her a steaming bowl of noodles. After eating some bites, Sue cried.

    “What is it?” the owner asked.

    “Nothing. I am just touched by your kindness! Even a stranger on the street gives me a bowl of noodles, but my mother chased me out of the house after a quarrel. She is so cruel!”

    “Girl, why did you think so? Think again. I only gave you a bowl of noodles and you were touched. Your mother had raised you since you were very born, why weren't you grateful and argued with your mom instead?”

    Sue was really surprised after hearing that.

    On the way home, Sue thought it over about what to say to her mother. She stopped in front of the door and saw her mother worried and tried after looking for her everywhere. When she saw Sue come back home, she was overjoyed and said eagerly(激动的), “Sue, come inside, honey. Are you hungry? I cooked rice and prepared the meal. Come in and eat while it is still hot.” Sue couldn't control herself any longer. She cried and hugged her mother.

    In our life, it's easy for us to appreciate the small actions of strangers, but for the relatives, especially our parents, we see their sacrifices(牺牲)as a matter of course. Parental love is the most precious gift we have been given since birth.