1. Environmental degradation

2. Cultural differences

3. Scientific and technological development

4. World peace

Broadly speaking, searching for some pictures to match these questions is more convincing and easier to understand;

You can also explore a problem in depth. ...

Let's talk about this problem from a general point of view, and then return to what we college students can do.

How to write it depends on LZ's own efforts ... Come on! ! You can use the internet to search for some well-founded arguments!