若直线$2ax-by+2=0$（$a>0,b>0$）被圆$x^2+y^2+2x-4y+1=0$截得的弦长为4，则$\frac{1}{a}+\frac{1}{b}$的最小值为(    )

生活在同一个星球上，人们沐浴着相同的阳光。然而，弱势群体却难以感受到应有的温暖，迫切需要大家的理解、信任、宽容和关爱。我国农民工为城市建设和经济发展做出了重大贡献，但他们面临着以下诸多的问题和困难（　　）

①社会保障  ②权益保护  ③子女就学  ④就业困难而生活无保障

完形填空

       An old man was dying. One by one his relatives visited him. Even relatives and friends he hadn't seen for years  1  him to say farewell. They all2their deep love for him. 3   each came to him, the old man held each person by their  4 and spoke to each. To one he said, “Yes, I love you.” To  5  he said, “I go without any ill will.” To a third one he said, “Peace be with you.”

        And so to each person he said such 6  words. Then the old man7Nasrudin (a wise man in the Middle East). When Nasrudin came in, he stood on one side,  8  everyone and listened to what they said and what the dying man said to them. After a while, Nasrudin 9  his hands in the air, and when everyone 10 to hear him, Nasrudin said , “Fools! Why didn't you visit him in his good  11? You didn't love him when he was healthy, but you love him when he is dying!”

      After that, Nasrudin turned to the  12  man and shouted, “Fool! Why didn't you live with such nice feelings all the days when you were13 and fully alive?” With that, Nasrudin left the  14. The old man 15  and said, “At last I’ve heard the   16 . It is a blessing to 17  having heard the truth.” The old man died  18 .

       What about the others? They returned to their  19   business of life and continued as they always had been. And Nasrudin? When he returned to his 20 just outside the old man's house, the donkey made a long high sound, “Hee-haw! Hee-haw!” Nasrudin said, “Yes, I know... You're right... Live well; die well...”