VOA慢速英语:研究称艾滋病药物与抑郁症、自杀无关

negative – adj. harmful or bad; unwanted

associate – v. to think of one person or thing when you think of another person or thing

metabolism – n. the chemical processes by which a plant or an animal uses food and water to grow and heal and to make energy

randomized – adj. of or related to something lacking aim, direction or rule

neural tube – n. a structure from which the brain and spinal cord form