VOA慢速英语:Worms Get Ready to Fly in Space

invertebrate – n. a type of animal that does not have a backbone

DNA – n. a substance that carries genetic information in the cells of plants and animals; an abbreviation of deoxyribonucleic acid

rotate – v. to move or turn in a circle

simulator – n. a machine that is used to show what something looks or feels like and is usually used to study something or to train people