经济理论提供工具,但现实世界的测试会完善它们。
Economic theory provides the tools, but real-world testing refines them.
生活的秘密在于给予。
每个人都有自己的故事。
可持续性不是一种趋势;而是我们共同对地球的责任。
"I write for kids because I was a kid who needed books."