approximate boundary value

例句：

1. 1.The temperature is approximately 20 degrees Celsius.
   温度大约是20摄氏度。
2. 2.The distance between the two cities is approximately 300 kilometers.
   两座城市之间的距离大约是300公里。
3. 3.The book's content is approximately accurate.
   这本书的内容大致准确。