VOA慢速英语:撒哈拉沙漠会“变脸”两万年一轮回

desolate – adj. an empty, lonely and sometimes sad place

fossil – n. part of an animal or plant from thousands of years ago that has been preserved in rock

dominant – adj. main or most important

sediment – n. solid substance that forms a layer at the bottom of a liquid

layer – n. an amount of a substance covering a surface, with each on top of the other

inhospitable – adj. not pleasant or easy to live in because of extreme conditions

disperse – v. to separate and go in different directions