例句：
1、The course allows students to progress at their own speed.
本课程允许学生按各自的速度学习。
2、He was driving at well over the speed limit.
他当时开车的速度远远超过了限制。
3、This course is designed so that students can progress at their own speed.
这门课的设计思路是让学生自己掌握进度。
4、It is vital to keep a check on your speed.
经常检查并控制你的'车速是至关重要的。
5、You should always keep to the speed limit.
什么时候你都不得超过最高速度限制。