These structures had been detected years earlier by echo-sounding instruments, but they had never been penetrated in the course of drilling.

这些结构在早些年曾被回声探测器探测到，但是它们从未被钻探过。

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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。

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I asked, my voice sounding like a shrill echo.

我问。我的声音象是尖利的回声。

youdao

I asked, my voice sounding like a shrill echo.

我问。我的声音象是尖利的回声。

youdao