variable-diameter number of hole

例句：

1. 1.The variable-diameter pipe is usedfor conveying fluids with varying pressures and temperatures.
   这种可变直径的管道用于输送压力和温度不断变化的流体。
2. 2.The variable-diameter valve allows theflow rate to be adjusted according to theneeds of the process.
   可变直径阀门可以根据工艺需求调整流量。
3. 3. The variable-diameter nozzle can produce a wide rangeof spray patterns, which is usefulin various industrial applications.
   可变直径喷嘴可以产生多种喷雾模式，适用于各种工业应用。