当介质流过流速式流量计时,推动叶轮旋转,利用叶轮的转速与水流速度()的原理就可以知道流量的大小。
A、成反比
B、成正比
C、相等
D、成等比数列
参考答案:B
_____he is only 8 years old,he knows more about science than his father.
A.But
B.Though
C.So
D.Because