sustainable - adj. involving methods that do not completely use up or destroy natural resources

density - n. the amount of something in a particular space or area

alleviation - n. the process of reducing the pain or trouble of (something) : to make (something) less painful, difficult, or severe

bare - adj. not covered by leaves, grass, trees, or plants

insurance - n. protection from bad things that may happen in the future — usually + against

distinguish - v. to notice or recognize a difference between people or things

scary - adj. causing fear

thatched - adj. made of dried plant material (such as straw or leaves)

roof - n. the cover or top of a building, vehicle, etc.