题干

有关分子运动,下列说法正确的是(   )

A:液体很难被压缩,说明分子间有引力

B:用手捏海绵,海绵的体积变小了,说明分子间有间隙

C:有霾天气大量极细微的尘粒悬浮在空中,说明分子在做无规则运动

D:在做墨水滴入水中的扩散实验中,我们看不到墨水的分子在运动

上一题 下一题 0.0难度 选择题 更新时间:2018-09-23 09:08:25

答案(点此获取答案解析)

D

同类题2

根据短文理解,选择正确答案。

    Our love of music and appreciation of musical harmony (和声) is learnt and not based on natural ability, a new study by University of Melbourne researchers has found. The researchers said previous theories about how we appreciate music were based on the physical functions of sound, the ear itself and a born ability to hear harmony.

    The study shows that musical harmony can be learnt, and it is a matter of training the brain to hear the sounds. So if you thought that the music of some foreign culture (or Jazz) sounded like the crying of cats, it's simply because you haven't learnt to listen by their rules.

    The researchers used 66 volunteers with a range of (一系列的) musical training and tested their ability to hear combinations (组合) of notes (音符) to determine if they found the combinations familiar or pleasing. They found that people needed to be familiar with combinations of notes. If they couldn't recognize the notes, they found the notes dissonant. This finding put an end to centuries of theories claiming (声称) that physical functions of the ear determine what we find attractive.

    The study found that trained musicians were much more sensitive (敏感的) to unpleasant notes than non-musicians. When they couldn't find the note, the musicians reported that the sounds were unpleasant, while non-musicians were much less sensitive. This shows the importance of training or nurturing (培养) the brain to like particular sound of combinations of notes, like those found in jazz or rock.

    Depending on their training, a strange chord (和弦) sound was pleasant to some musicians, but very unpleasant to others. This showed us that even the ability to hear a musical note is learnt.

    To confirm (证实) this finding, they trained 19 non-musicians to find the notes of a random (随机的) selection of western chords. Not only did the participants' ability to hear notes improve rapidly; the chords they had learnt sounded more pleasant—regardless of (不论) how the chords were played.

    The question of why some combinations of musical notes are heard as pleasant or unpleasant has long been debated. “ We have shown in this study that for music, beauty is in the brain of the beholder(观看者),” a researcher said.