皂化值是挥发油中的（）
A．酸值加皂化值
B．皂化值减酸值
C．酸值减皂化值
D．羧酸和酚类成分总和
E．酸值与酯值之和
参考答案：E
叙述泄漏气体爆炸现场的特点？
---I broke the window.
---You___ play football near the window.
A.should B. shouldn’t C. had better
