题目选项分析

For the past 50 years, due to changes in lifestyle and recreational activities, the population of the United States has become increasingly kyphotic, displaying poor posture and spine curvature, and it will probably have what is estimated as100 million people with back problems next year, more than any other nation in the world will.

For the past 50 years, due to changes in lifestyle and recreational activities, the population of the United States has become increasingly kyphotic, displaying poor posture and spine curvature, and the country will probably have100 million people with back problems next year, more than any other nation in the world will.