计算复杂性的研究告诉我们，有些问题本质上是困难的，无论我们的算法多么聪明。
"The study of computational complexity teaches us that some problems are inherently difficult, no matter how clever our algorithms are."
了解心灵的方法是对其进行逆向工程：弄清楚自然选择设计它来完成什么任务。
Collaboration is key—governments, businesses, and communities must work together for sustainable forests.
解释：大部分鸟类都是雄性的，而雌鸽却是雌性的，说明了鸟类性别的特殊性。