When did the first measurement of the speed of soundtake?
第一次测量声速是在什么时候？
2
Birds prefer not to take any chances—and to steer clear of all insects that look, sound, or fly like a bumblebee to avoid being stung.
鸟类宁愿不去尝试更多的机会——它们要避开所有如大黄蜂的长相、声音和飞行模式的昆虫，以避免被蛰。
3
Although full integration of sound into movies was complete by 1930, it would take a bit longer for films to regain their stylistic elegance and dexterity.