油漆粘度一旦调配好就不允许改变。
参考答案：错
We shouldn’t complain about being poor--- many families are ____ than we are.
A．worse off
B．badly off
C．well off
D．better off
A声级采用的是（）方倒置等响曲线作为计权网络所测得的声压级。
A.40
B.50
C.80
D.100
