問題詳情
20. Researchers are increasingly turning their attention to _____ exacerbate existing health conditions and lead to hearing loss in vulnerable
populations.
(A) noise pollution can
(B) that noise pollution
(C) how noise pollution
(D) how noise pollution can
參考答案
答案：D
統計：A:0,B:1,C:6,D:16,E:0
難度：計算中