Heat exhaustion is a condition caused by______to sunlight or another heat source which often results in dehydration and salt depletion.
【正确答案】
B
【答案解析】本题空格处是说由过度暴露在阳光下引起的。B项overexposure“过度暴露”符合题意。其他三项a reaction to“反应”，a limitation of“局限”，an absence of“缺乏”都不正确。