問題詳情:
It’s best to stay indoors , ________when PM2.5 has reached dangerous levels.
A. exactly B. possibly C. generally D. especially
【回答】
D
知識點:副詞
題型:選擇題
問題詳情:
It’s best to stay indoors , ________when PM2.5 has reached dangerous levels.
A. exactly B. possibly C. generally D. especially
【回答】
D
知識點:副詞
題型:選擇題