疾病预防及控制
“动员全世界的力量推进正义的事业”
On issues of global concern, "we will mobilize the world to work with us," President Obama said in his last State of the Union address.
空气污染对人体的危害有多大
When we live in cities, we breathe dirty air, which is bad for us. It causes many diseases. But there are ways to stop the pollution.