美国不应该试图在世界各地传播民主。
The United States should not try to spread democracy around the world.
The PAC learning framework provides a formal way to quantify the learnability of a concept class.
Every tree planted today is a legacy for generations we will never meet.
We hope that through Pinduoduo, more people can enjoy the benefits of the internet.
La realidad es solo una de las infinitas posibilidades que nuestra imaginación puede concebir.