Ren trong. Ren đó ở trong nắp chai nước ngọt.
Nắp chai nước ngọt có ren. Vậy ren đó có tên gọi là ren bảo vệ.
Choose the best answer.
We are looking for ____ place to spend ____ night.
Please turn off ___ lights when you leave ___ room.
I like _____ colorful costumes of ____ ethnic minority people in Vietnam.