不适合用于采集气态和蒸气态物质的吸收管(瓶)的是()。
A.气泡吸收管
B.冲击式吸收管
C.多孔筛板吸收管
D.多孔筛板吸收瓶
参考答案:B
若p,q都是质数,以x为未知数的方程px+5q=97的根是1,则p2-q=______.
The way he did it was different ____ we were used to.
A.in which
B.in what
C.from what
D.from which