2 sentences

1. 缺乏核心技术是这家公司的致命伤。

   quē​fá hé​xīn jì​shù shì zhè jiā gōng​sī de zhì​mìng​shāng.

   The lack of core technology is this company's Achilles' heel.

   Source: Dong Chinese Dictionary

2. 这一刀正中心脏，是导致他死亡的致命伤。

   zhè yī dāo zhèng​zhōng xīn​zàng, shì dǎo​zhì tā sǐ​wáng de zhì​mìng​shāng.

   The stab went straight to the heart and was the fatal wound that caused his death.

   Source: Dong Chinese Dictionary