instructive mark

例句：

1. 1. The teacher gave the students some instructive notes to read during the break.
   老师给学生一些有指导意义的笔记，让他们在休息时阅读。
2. 2. The book is full of instructive information about history.
   这本书充满了有关历史有指导意义的信息。
3. 3. His lectures were highly instructive and helped me understand complex concepts better.
   他的讲座非常有指导意义，帮助我更好地理解复杂的概念。