国家开放大学 / 高级英语阅读（2）
The number of children who are taught at home is________.
1.5 million
1.5% of the school-age population
2.5% higher than last year
2.5 million
1.5 million
1.5% of the school-age population
2.5% higher than last year
2.5 million
参考答案：