VOA慢速英语:研究发现称充足的睡眠可以降低受伤的风险

muscle –n. a body tissue that can contract and produce movement

positive –adj. good or useful

impact –n. a powerful or major influence or effect

musculoskeletal –adj. related to the muscular and skeletal systems of a human body

caffeine –n. a substance that is found especially in coffee and tea and that makes you feel more awake

nicotine –n. a poisonous substance in tobacco that makes it difficult for people to stop smoking cigarettes

mask –n. a covering for your face or for part of your face

earplugs –n. a piece of soft material that you put in your ear to keep out water, noise, etc.