Which word in Vietnamese is solid but still falls?

Not everyone can find the answer to this Vietnamese question, please think carefully and find the solution.

This Vietnamese riddle makes many people shake their heads in defeat: "Which word in Vietnamese is certain but still falls?". Only people with a rich language vocabulary can find the answer.

With your knowledge of Vietnamese, is it easy to find the answer to this puzzle?

Which word in Vietnamese is solid but still falls?

If you find the answer in the shortest time, scroll down to the comments to record and see how many people think the same as you.

Lam Hoang

Source: https://vtcnews.vn/tu-nao-trong-tieng-viet-chac-chan-nhung-van-nga-ar952373.html