2 sentences

1. 你的美式英语无懈可击。

   nǐ de Měi​shì Yīng​yǔ wú​xiè​kě​jī.

   Your American English is impeccable.

   Source: OpenSubtitles

2. 他的逻辑非常严密，简直是无懈可击。

   tā de luó​ji fēi​cháng yán​mì, jiǎn​zhí shì wú​xiè​kě​jī.

   His logic is very tight, practically flawless.

   Source: Dong Chinese Dictionary