阅读下面短文,从每题所给的A、B、C三个选项中选出可以填入空白处的最佳选项。
Ara, 5 years old, helps watch the 1 in the green fields every day. She asks her parents, "Can we 2 one of them?" Her father says, "You need to do much work. You need to learn about cows first."
First, they go to a good farm. Green and fat grass is everywhere. The clean cows are eating grass happily. They milk a cow, and get lots of 3 . But the second farm is different. The cows are not 4 . When Ara asks about the milk, the farmers shake their heads.
Ara wants to do things to help the 5 cows. Finally, she gets a plan(计划) with her parents. She asks the first farmers to help the second farmers, and they say 6 . So they have a meeting and the first farmers share 7 experience(经验). Their advice is very helpful, and everyone learns a lot.
Weeks later, the 8 farm becomes clean. The farmers get much milk. They 9 Ara and plan to pass the help to other people. Ara's father says to her, "You really did a good job!"
In the end, Ara doesn't keep a cow, 10 she is happy because she helps those cows and farmers to be better. "One can have good change to the world at any age," she is so glad for herself.