书城教材教辅科学读本(英文原版)(套装1-6册)
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第223章 第三册(48)

The birds of prey have strongly-jointed toes, with sharp hooked talons. They use them for seizing their prey. The perching-birds have long, slender toes, for grasping the twigs. They rest securely on the branch by the mere bending of the knee.

Lesson 16

Birds-More about Legs and Feet

"You remember our talk about the woodpecker, Norah?" said Fred.

"Oh yes," said Norah. "He lives on worms and grubs which eat their way into the woody stems of the trees. He has a wonderful beak for boring into the trees, and a wonderful tongue for catching his prey when he has found out where they are.""Quite right," replied Fred. "Now tr y and remember something more. These birds live entirely in the trees be- cause their food is in the trees, and in the trees they are extremely nimble. You would besurprised if you could see one of them run up the rough bark of a tree.