: Cho mạchđiệncósơđồnhưhìnhvẽ: Biết, E1 = E2 = E3 = 3V, r1 = r2 = r3 = 1
R1 = R2 = R3 = 5
, R4 = 10
Tính suất điện động và điện trở trong của bộ nguồn và cường độ dòng điện
trong mạch chính

Sounds propagates through some kind of medium. usually it's air, but it goes just as well through solid objects like walls, windows etc. a soundwave will compress the (air)molecules in front of it, and if this increased density wave hits your ears, you register it as sound. solid objects like walls are a lot denser than air, this means that they will damp a wave, but also carry it easier.

If you are a plato user the answer would be "a decrease in the overall volume of gases" i just completed the test and this was the answer. hope it ! (:

Answer a descending mass of air will have its temperature increase because of the pressure exerted on it, because its temperature increases it will also be able to hold more water and feel drier;