2 sentences for 外壳 (wài​ké — hull)

1. 这种潜艇的外壳是由钛合金制成的。

   zhè zhǒng qián​tǐng de wài​ké shì yóu tài​hé​jīn zhì​chéng de.

   The hull of this submarine is made of titanium alloy.

   Source: Dong Chinese Dictionary

2. 潜艇的外壳必须能够承受深海的巨大压力。

   qián​tǐng de wài​ké bì​xū néng​gòu chéng​shòu shēn​hǎi de jù​dà yā​lì.

   The hull of a submarine must be able to withstand the immense pressure of the deep sea.

   Source: Dong Chinese Dictionary