下列食物中，富含蛋白质的是（　　）

完形填空

    "There once was a beggar who loved to hear himself sing.He lived1a dustbin next to a supermarket.He had the most amazing voice.No one would listen to him,2.Cats and dogs would come to sing along.All animals would come to hear this sound.No3though.His4audience were the animals.Even without people to sing to.the man was filled with5for he loved his voice.

    Then one day,a little girl was on her way to the supermarket.The man was singing one of his favorite songs.The little girl6him and wondered what that noise was.She began7around every corner until she found him. The girl's eyes began to grow wide as she saw the man in his8clothes.She asked him to sing,with no9of danger in her voice.This shocked the man.He sang for the girl with joy in his eyes.Although it was nice to be 10to sing,it was also nice to have an audience.He sang until they heard the girl's mother11for her.The girl quickly said12and ran off.

    The girl returned the next day and asked him to sing.13he sang for the little girl.After a few songs,she left14the call of her mother.She came the day after,with an older woman.This was the girl's15.She did not seem to mind being led behind a16dustbin.The girl asked the beggar to sing.The man sang his heart out for the17of them to hear.The mother's frown began to18and a smile began to appear.The days after were full of cheerful singing and the audience of two19,they would bring more people to listen.The beggar continued to sing until he could not sing anymore.20he loved his voice anymore.

如图，已知抛物线y=ax²+bx+c（a＜0，c＞0）与x轴交于A，B两点，与y轴交于点C，其对称轴l为x=﹣1，直线y=kx+m经过A，C两点，与抛物线的对称轴l交于点D，且AD=2CD，连接BC，BD．