第三人稱單數(shù)：roofs；現(xiàn)在分詞：roofing；過(guò)去式：roofed；過(guò)去分詞：roofed。
例句：
We could see the stars through an opening in the roof.
我們從屋頂?shù)男《茨芸匆?jiàn)星星。
The stone made a dent in the roof of the car.
石頭把車頂砸了個(gè)坑。
The roof of the tunnel fell in.
隧道頂部塌了下來(lái)。