Hxen.com's tips：Every day persisted can learn English well!-->■Learn English Everyday■
edit – v. to make changes to something, such as a piece of writing, by adding or removing parts of it
DNA (deoxyribonucleic acid) – n. a substance that carries genetic information in the cells of plants and animals
executive – n. a person who supervises or directs other people in a company or organization
