警jǐng察chá正zhèng在zài调diào查chá这zhè起qǐ案àn件jiàn。

The police are investigating this case.

我wǒ们men做zuò了liǎo一yí个gè市shì场chǎng调diào查chá。

We did a market survey.

他tā被bèi叫jiào去qù接jiē受shòu调diào查chá。

He was called in for questioning.

警jǐng察chá正zhèng在zài调diào查chá这zhè件jiàn事shì。

The police are investigating this matter.

我wǒ们men做zuò了liǎo一yí份fèn市shì场chǎng调diào查chá。

We carried out a market survey.