循环小数

例句：

1. 1. The temperature in this room is around 20°C, which is a common temperature for a room with a window.
   这个房间里的温度大约是20°C，这是有窗户的房间常见的温度。
2. 2. When calculating the area of a circle, we often use the formula A = πr², where r is theradius and π is a constant approximately equal to 3.14159.
   在计算圆的面积时，我们经常使用公式A = πr²，其中r是半径，π是一个常数，大约等于3.14159。
3. 3. The cost of living in New York City is much higher than in other cities, making it difficult for many people to affordhousing.
   纽约市的生活成本远高于其他城市，这使得许多人难以负担住房。