脚心

例句：

1. 1. He sat on the floor, his feet resting on his knees.
   他坐在地板上，双脚搁在膝盖上。
2. 2. The child was crawling on the grass, her feet touching the ground.
   那个孩子正在草地上爬行，双脚触地。
3. 3. She walked barefoot on the beach, feeling the sand between her toes.
   她赤脚走在沙滩上，脚趾间感受着沙子。