灭火后的防护区应通风换气,地下防护区和无窗或固定窗扇的地上防护区,应设机械排烟装置,排风口宜设在防护区的()并直通室外。
(A)上部
(B)中上部
(C)中部
(D)下部
参考答案:D
根据句意完成句子。
1. —_____ is the hat?
—It's on the bed.
2. —Where _____ his keys?
—They're on the dresser.
3. —Where are the books?
—I don't _____.
4. Please _____ (带给) some things to me.
5. — _____ you take the book to my sister?
—Yes, I can.
氨化作用