Baboons(狒狒) live in Africa. They are like monkeys. Most people think daddy baboons don't know their babies. But scientists (科学家) find that daddy baboons know how to help their babies. The daddy baboons are smart.
Joan Silk is a scientist. She studies the baboons for 3 years. She says the daddy baboons are happy to see their babies. They have big teeth to help the babies to eat hard things. Mother baboons are small. And they live in a place. When a mother baboon gives birth(分娩), she often has only one baby. Baby baboons have fur. They are very cute.
During the day they eat things. At night, they sleep in the trees. Most children like baboons because they look like the man.

南北美洲的分界线是____ 。