VOA慢速英语:How Does Long-Term Space Travel Affect Humans?

telomeres – n. the items on the end of a chromosome.

stressful – adj. full of or causing stress or making you feel worried or anxious

hormone – n. a natural substance that is produced in the body and that influences the way the body grows or develops

accuracy – n. freedom from mistake or error

instantaneous – adj. happening very quickly, in an instant

painstaking – adj. done with great care and effort

tedious – adj. boring or too slow or long