它的振动幅度取决于引力场的强度。Its oscillation depends on the strength of the gravitational field.振动幅度的大小决定声音的大小.The amplitude of the vibration determines the loudness of the sound.膜片振动,这使得周围的空气也动荡起来.The diaphragm vibrates , thus setti...
汽船向我们嘟嘟鸣笛时，甲板上的水手们饶有趣味地挥着手。Steamers tooted at us as sailors on deck waved in amusement.一路上，汽船在好几个港口停靠。The steamer calls at several ports along the way.汽船一离开码头就加快了速度.The motorboat put on speed as soon as it left the pier....
Hundreds of people jammed the boardwalk to watch...数百人挤在木板人行道上观看。Hundreds of people jammed the boardwalk to watch.数百人挤在木板人行道上观看。I bought some novelties on the boardwalk.我在海滨人行道上买了一些新颖的小玩意儿.The museum is a collection of m...