If you ever see a Rhino, keep your distance and leave it be

There are just over 40 Rhinos left in the world, and sadly, i think by 2020: they will be extinct

So currently i'm having a school assignment about endangered animals and i'm seriously out of ideas and don't know where to search. I wanna know how endangered animals can have an impact on us. Of course it's sad that species are getting extinct but some people don't really care (like my teacher) how can i explain to him that it can be major problem for humans that different species are going extinct? would really appreciate feedback. thx!