缺词填空。 I have lived in the countryside since I was a child. There were many k   1 of birds there when I was young. Every morning, lots of sparrows liked singing and j   2 in the trees outside my window, while the swallows were busy flying out to f    3 food for their babies. Sometimes in the afternoon, I could even see eagles f    4 in the sky. After twenty years, many of them cannot be seen now. I can seldom see the eagles o   5 the swallows. The n    6 of the sparrows is getting smaller. Only some of t    7 sing in the morning. Why do the birds leave here? First I think it is because the environment is becoming worse now. The birds can't find e    8 food for themselves and their babies. Second I think it is because people often k    9 them for food. Without the birds around, we won't feel happy any more. So we must p   10 them. Why don't we do something to help today?