normal flow rate的用法和样例：
例句
- Criteria for selection is minimum flow, normal flow, maximum flow and pressure drop across the valve.
选型标准是最小流量，正常流量，最大流量和通过阀门的压降。 - Pages are reformatted and compressed before being sent to the phone, so they only use about one fifth of their normal amount of traffic.
发送之前，对面进行重定格式和压缩，所以流量仅是正常流量的五分之一。
