Cách sử dụng
Flint is a type of hard rock that can make sparks when it is hit against steel or another hard object. It was used a long time ago to start fires before matches were invented. Nowadays, you might hear the word flint used to describe something that is very hard or tough, like a flinty stare or a flinty personality. It can also refer to a town in Michigan called Flint, which is known for its history of automobile manufacturing.