The boy has learned many lessons. These lessons are about human

The boy has learned many lessons. These lessons are about human kindness, (simple sentence)
【正确答案】：The boy has learned many lessons about human kindness.
【题目解析】：我们用介词about（关于）将以上两句单句变成一句单句：这个男孩学到了许多关于人类善良的知识。