In most cities and towns, the high volumes of road traffic become a problem. What are the causes of that and what actions could be taken to solve the problem?

兼职要求学生遵守纪律并相应地分配时间。

竞争激烈的运动项目不适合年纪特别小的孩子。

The speaker suggests ostrich farms are profitable because____

男女同校会大大分散学生学习的注意力。