Platypuses
　Platypuses live in Australia/and they are mammals.// Usually,/mammals bear babies/and raise them with milk.// 例 In contrast,/platypuses lay eggs.// The eggs hatch in about ten days,/then mothers give milk to their babies.// Scientists say/that this was common for ancient mammals.// In other words,/platypuses are “living fossils.”//
　Australia is isolated from other continents/and platypuses could escape from many enemies.// In addition,/they live in rivers for protection,/so platypuses have survived until today.//