n.半衰期( half-life的名词复数 );
例句:
One half of the world does not know how the other half lives.
各在天一方,世事两茫茫.
Half the world knows not how the other half lives.
世界上有一半的人不知道另一半人如何生活.
One half of the world do not know the other half lives.
各地各风,难以沟通.