Shutters are wooden or metal covers fitted on the outside of a window. They can be opened to let in the light, or closed to keep out the sun or the cold. 百叶窗
noun [专属名词]百叶窗,活动护窗;(照相机的)快门;(风琴的)开闭器
She opened the shutters and gazed out over village roofs. 她打开了百叶窗,朝村里的房顶望去。