Hippos are being endangered mainly because the poachers hunt them for their meat and their ivory teeth
A group of organs that work together to perform a common function is an organ system
It depends on where your going and how many people are going to the trip. But in my opinion I think about 3 times because you need to make stops when you need to use the restroom and when your hungry.
Sorry if I am not right :(
I hope I helped you have a great day :)
