concentric circle

例句：

1. 1. The planets revolve aroundthe sun in a concentric circle.
   行星围绕太阳在同心圆中旋转。
2. 2. Thecity is surrounded by a concentric circleof parks and gardens.
   这个城市被一圈公园和花园所环绕。
3. 3. Thescientists found a concentriccircle of minerals in the rock.
   科学家们在岩石中发现了一个同心圆状的矿物层。