15-20

例句

释义:
类别:全部全部,口语口语,书面语书面语,标题标题,技术技术
来源:全部全部,字典字典,网络网络
难度:全部全部,简单简单,中等中等,
2.
Once you've done 2 minutes a day for a week, increase it to 5, and stick with that for a week. In a month, you'll be doing 15-20.