The averagehead trauma, ambulance ride, emergency room visit, x-rays.
一般的头损伤，救护车、急诊室、医生费用等等。
2
The averagehead weighs 7 to 8 pounds—a lot of pressure to be putting on your face every night.
头部平均重量是7-8磅——趴着的话对脸部可是不小的压力。
3
By 2050, the global population is projected to rise to 9 billion, so average per head emissions will have to be lower than 2 tonnes per year on average.