Natural experiments are a powerful tool for understanding causal relationships in the real world.
The world is a book, and those who don’t travel read only one page.
那些将环境法规视为机遇而非障碍的公司将会蓬勃发展。
It is a curious subject of observation and inquiry, whether hatred and love be not the same thing at bottom.
科学家价值的真正衡量标准不在于所获得的荣誉，而在于他们的工作对世界的影响。