Kevin lived in a village in Africa. One morning, the teacher came into Kevin's classroom with a new girl. "Hi, guys! My name is Jenny. I am from America. I came to Africa with my dad. It's nice to meet everyone," the girl said.
Kevinnoticed(注意) that he looked different from Jenny. As soon as school was over, he ran home to ask his mother, "Mom, there is a new student Jenny in our class today. She comes from the US. Everyone in Africa has curly hair, right? Then, why is Jenny's hair straight?"
Mom thought for a minute and said, "It's always hot in Africa. Curly hair is like asponge(海绵) with manyholes(洞), so the air can get in and out easily. If your hair was like Jenny's straight hair, you wouldn't be able tostandtheheat(热). Our curly hair isnecessary(必要的)!"
