阅读下列短文，从短文后所给的A、B、C三个选项中选出能填入相应空白处的最佳选项。
An old man lived with his little grandson. Every day the old man got up early to read books.His grandson wanted to be just like him and tried to copy him every 1 he could.
One day the grandson asked, “Grandpa, I want to read books as you do. But I don't understand it, and I always forget 2 I close the book. What good does 3 do?”
The grandfather quietly turned from putting 4 in the stove and replied, “Take this coal basket down to the river and bring me back a basket of water.”
The boy did as his grandpa said, but all the water leaked（漏）out before he got back home.
The grandfather laughed and said, “You'll have to walk faster next time.”
The next time the boy ran faster, but the basket was still empty before he 5 home. The boy said, “see, Grandpa, it's 6 to finish this task!”
“Is it no use?” the old man said. “ 7 the basket.”
The boy looked at the basket and for the first time realized that the basket was 8 . Instead of a dirty old coal basket, it was 9 inside and out.
“My child, that's what happens when you read the book. You might not understand or remember everything, but the 10 will change you inside and out. That is the work of reading in our lives.”
