专八

简答题 __________.

参考答案:暂无进入在线模考
harmful。本题的出题点在情态动词处(must)。题干问在评估空气质量阶段,要测出人体接触多少污染物是 _____ 。讲座中提到Scientists must then determine how much exposure to pollutants is harmful,故得答案harmful。