読み方：なかせん（名詞） inner plug for a bottle, prevents leaks and is often covered by a cap.
就是瓶蓋裏面那個橡膠的小墊子,瓶子上會寫是因為壹般中獎信息都應在瓶蓋裏面,也就是那個墊子上,那個東西就叫做 中栓