题目

如图，在平面直角坐标系中，点P的坐标为（a、b），且a、b满足a2＋4a＋4＝ ， 点B为x轴上动点，过点P作PC⊥y轴于点C. （1） 求O、P两点间的距离； （2） 如图1，点A为y轴正半轴上一点，连接PA、PB、AB，若B（﹣4，0），且2∠APB＝90°＋∠PAC，求点A的坐标； （3） 如图2，过点P作PD⊥PB交y轴正半轴于点D，点M为BD的中点，点N（﹣1，0），则MN的最小值为（请直接写出结果）.One day last summer, watching the boys and girls trying to catch butterflies I remembered something happened when I was young．When I was a boy of 12 in South Carolina, something happened to me that cured me forever of wanting to put any wild creature in a cage.We lived on the edge of a wood, and every evening at dusk the mockingbirds would come and rest in the trees and sing. No musician can sing more beautiful than the birds. I decided that I would catch a young bird and keep it in a cage and in that way would have my own private musician. I finally succeeded in catching one and put it in a cage. At first, the bird flied about the cage, but eventually it settled down in its new home. I felt very pleased with myself and looked forward to some beautiful singing from my tiny musician.I had left the cage out, and on the second day my new pet’s mother flew to the cage with food in her mouth. The baby bird ate everything she brought to it. I was pleased to see this. Certainly the mother knew better than I how to feed her baby.The following morning when I went to see how my bird was doing, I discovered it on the floor of the cage, dead. I was shocked! What had happened! I had taken good care of my little bird.Arthur Wayne, the famous ornithologist, happened to be visiting my father at the time, hearing me crying over the death of my bird, explained what had occurred. “A mother mockingbird, finding her young in a cage, will sometimes bring it poison berries. She thinks it better for her young to die than to live in cage.”Never since then have I caught any living creature and put it in a cage. All living creatures have a right to live free.【小题1】Why did the writer catch a mockingbird when he was a boy of 12?A．He had just got a new cage.B．He liked its beautiful feather.C．He wanted a pet for a companion.D．He wanted it to sing for him.【小题2】The mockingbird died because it ______. A．drank the poisonous water by mistakeB．was frightened to deathC．refused to eat anythingD．ate the poisonous food its mother gave it【小题3】An ornithologist probably means ______.A．a religious personB．a kind personC．an expert in birdsD．a schoolmaster【小题4】What is the most important lesson the writer learned from the incident?A．Freedom is very valuable to all living things. B．All birds put in a cage won’t live long.C．You should keep the birds from their mother.D．Be careful about food you give to baby birds.