If the two media have really different densities, like air and water, then most of the energy is going to be reflected back, very little of it will keep going and get transmitted into the new medium.
而如果这两种介质的密度相差较大,就像空气和水那样,那么大部分的能量将会折射回来,只有一小部分会继续传播进入到新的介质中。
It causes environmental problems, like air pollution and temperature rise.
它可导致环境问题,如空气污染和温度上升。
Stories were like air to me and while other kids played ball or went to parties, I lived out adventures through the books I checked out from the library.
故事对我来说就像空气一样,当别的孩子打球或参加聚会的时候,我却通过从图书馆借来的书,过着冒险般的生活。
Chemical sprays like air fresheners,hair spray, household cleaning products and even strong perfumes can also trigger an asthma attack.
VOA: special.2009.07.28
dT/dp is mu JT. So for a real gas like air, this is a positive number. It's not zero.
所以对于像空气这样的真实气体,这是一个正数,不等于零。
So like, right now, I'm kind of looking into the military and the air force
所以现在我想参军和空军,
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