Choose the best answer.(根据短文内容，选择最恰当的答案)

    When spring comes, everything begins to wake up. Many animals in the woods have been asleep all winter. Birds have been away. Under the snow, the ground has been hard and still.

      Then, all at once, it is spring! The days begin to grow long. From the south, the birds fly back. They are ready to build their nests. Animals wake up and start to look for food.

    Trees grow new leaves. Plants begin to flower. Baby birds and animals are born. Farmers are busy growing crops and vegetables from morning until night.

    In many countries, people greet the spring with songs and dancing. Springtime is a happy time all over the world.