公证是保障交易安全的重要手段。

Gōngzhèng shì bǎozhàng jiāoyì ānquán de zhòngyào shǒuduàn.

Notarization is an important means to ensure transaction security.

他委托律师进行文件公证。

Tā wěituō lǜshī jìnxíng wénjiàn gōngzhèng.

He entrusted a lawyer to notarize the documents.