VOA慢速英语:研究称空气污染降低智力

exposure – n. the fact or condition of being affected by something or experiencing something

range – n. a sequence, series, or scale between limits

sample – n. a representative part or a single item from a larger whole or group especially when presented for inspection or shown as evidence of quality

verbal – adj. of, relating to, or consisting of words

consistent – adj. always acting or behaving in the same way

hypothesis – n. an idea or theory that is not proven but that leads to further study or discussion

participant – n. a person who is involved in an activity or event : a person who participates in an activity or event

occur – v. to come into existence

income – n. money that is earned from work, investments, business, etc.

engage – v. to take part in or cause to take part in something