Seasons

    In many places, the weather changes during the year. These changes are called seasons. In the north and south, there are four seasons in a year. Each season brings changes that are important for plants and animals that live in different parts of the world.

    Spring starts when the day and night are the same length(长度). The weather gets warmer and sunnier. Trees and plants start to grow. Many animals have their babies in spring.

    Summer begins on the longest day of the year. In the north, this is on June 2lst. Summer is usually the warmest and sunniest time of the year. Fruit grows on trees and plants. Young animals grow bigger and stronger.

    Autumn starts when the day and night are the same length again. During autumn, the leaves change colour and fall from the trees. Some animals collect(收集) food before winter comes.

    Winter begins on the shortest day of the year. In the north, this is on December 21st. The weather is colder and in some places there is lots of snow. Plants and trees stop growing. Some animals, like bats(蝙蝠) and bears, find places to hide and sleep. This is called hibernation(冬眠).