Zippers have teeth and other questions about inventions / I wonder why.zippers have teeth and other questions about inventions / I wonder why zippers have teeth and other questions about inventions Leaves change color and other questions about plants Romans wore togas and other questions about Rome / There's a hole in the sky and other questions about the environment Horses wear shoes and other questions about horses / Greeks built temples : and other questions about ancient Greece Mountains have snow on top and other questions about mountains I sleep and other questions about my body /