oral presentation

Today we have done the oral presentation in the class, from my point of view, every classmate has done a good job.
The class have made my life busier, but that also have made my life more interesting.
The preparation of the oral presentation took me about 10 hours, 10 hours for 7 minutes, sounds not really effective, so, I think the problems time manage, I think i am not good in time manage.
i wonder how my classmate prepare their presentation, and how long they spend on the prearation, I would like to know if someone share with me. To know different ways to prepare would be a good thing.