normal polyester resin

例句：

1. 1. The normal temperature for this region is 20 degrees Celsius.
   这个地区的正常温度是20摄氏度。
2. 2.He has a normal height and weight for his age.
   他在这个年龄的身高和体重是正常的。
3. 3. The normal course of the disease is to improve gradually.
   这种疾病的正常病程是逐渐改善。