题干

以下几个实验现象中,能说明声音产生条件的实验现象是(   )

A:放在钟罩内的闹钟正在响铃,把钟罩内的空气抽出一些后,铃声明显减小

B:使正在发声的音叉接触水面,水面溅起水花

C:吹笛子时,手指按住不同的孔便会打出不同的声音

D:把正在发声的收音机密封在塑料袋内,然后放入水里,人们仍能听到收音机发出的声音

上一题 下一题 0.0难度 选择题 更新时间:2018-11-21 06:16:18

答案(点此获取答案解析)

B

同类题3

阅读理解

    English is full of colorful phrases to describe shyness. Someone shy might be called shrinking violet or a wallflower, while for especially nervous types we have the curious expression: they wouldn't say boo to a goose.

    None of these are traditionally seen as positive descriptions, even if you like geese. In a culture of go-getting, high achievers, shy people don't come first. Or that's what the self-help industry would have you believe. Bookshops are filled with vital tomes(巨著) that promise to help beat social fears and find success in life, love and business. That is why one book, Shrinking Violets: A Field Guide to Shyness, bucks the trend. It became a sudden success across English-language media recently for its new take-on shyness.

    Author Joe Moran says that despite struggling with shyness and longing for loneliness all his life, being shy can also be "a gift". Freed from the constant urge to participate and compete in social situations, people are liberated to look at the world in new ways, and gain fresh insights.

    Indeed, many of the world's great thinkers and artists are introverts(内向的人). Scientists Charles Darwin and Albert Einstein preferred their own company; actress Keira Knightley often finds herself tongue-tied at parties; and Harry Potter author JK Rowling claims she used to be too nervous to even borrow a pen.

    Moran told BBC Future: "I think shyness probably does turn you into an amateur anthropologist(人类学家), really-you are more likely to be an observer."

    So, while extroverts make all the noise, they don't necessarily have the best ideas.

    If you're shy, you've probably known this for a long time. You just don't shout about it.