Ib tug cwj mem ballpoint yog ib tug cwj mem uas yob tawm qhov nruab nrab ntawm kev sau ntawv los ntawm ib lub pob nyob rau pem hauv ntej ntawm tus cwj mem los yog refill.
A ballpoint pen is a pen that uses tiny spinning balls, made of brass, steel, or tungsten carbide, that release ink onto the paper as you write. The ballpoint pen is very different from its predecessors—reed pens, quills, metal-tipped pens, and fountain pens.
