One possible version:
May I have your attention, please? Now I’d like to make a speech here. Nowadays, some of us students have formed some bad habits on campus. For example, some students leave the lights on in the daytime or leave water running after washing. Some leave too much food on the table after eating in the canteen. Besides, waste paper and books can be seen everywhere. So it is high time that we had to deal with the problems.
As is known to all, these bad habits will have bad influence on our character and behavior. What’s worse, they can not only increase our cost at school and add financial burden to our parents, but also waste the limited resources.
If we reduce the waste, we will change the present situation.
That’s all. Thank you!