Many parts of the world have four seasons. They are spring, summer, autumn and winter. In spring, the weather becomes warmer and the days get longer. Plants begin to grow and many animals have babies. Summer is the hottest season. Plants grow fast. In autumn, the weather turns cool. Trees may lose their leaves. Some birds fly to warmer places. Winter is the coldest season. Plants stop growing and many trees are bare(光秃秃的).
