谨慎 (jǐn shèn): осторожный

When doing experiments, you must be cautious; the slightest carelessness could cause problems.

He drives very cautiously; at intersections, he always slows down first and only goes through after making sure it's safe.

Before signing a contract, you should carefully check every clause to avoid future disputes.

She has a cautious personality and never easily trusts strangers, so she is rarely deceived.