So was born the echo-sounding apparatus, now in general use in ships.

这样就产生了目前各种船舶上普遍应用的回声探测仪。

youdao

So was born the echo-sounding apparatus, now in general use in ships.

这样就产生了目前各种船舶上普遍应用的回声探测仪。

youdao