实验室中测定岩心渗透率实验中，通过岩心的流量与（）成正比
A、流体的密度
B、流体的粘度
C、岩心的长度
D、岩心截面积
参考答案：D
_____ maths is concerned, Tom is the best student in our class.[ ]
A. As long as
B. As soon as
C. As for
D. As far as
用三针测量梯形螺纹时，主要是测量梯形螺纹中径尺寸。( )
