先通读下面的短文，掌握其大意，然后在每小题所给的A、B、C、D四个选项中，选出可以填入空白处的最佳选项。
Two brothers decided to dig a deep hole behind their house. As they were working, a couple of older boys 1 to watch.
“What are you doing?” asked one of the 2.
“We plan to dig a hole all the way through Earth!” one of the brothers answered 3.
The older boys began to laugh, telling the younger ones that digging a hole all through Earth was 4.
After a long silence, one of the diggers 5 a jar full of spiders, worms and a wide types of insects. He removed the lid (盖子) and 6 the wonderful things to the visitors.
Then he said quietly and 7 , “Even if we don't dig all the way through Earth, look at what we've found along the way!”
Their goal was far too ambitious (有雄心的), but it did cause them 8. And that is what a goal is 9 — to cause us to move in the direction we have chosen.
But not every goal will be fully 10 . Not every job will end 11. Not every hope will come to pass. Not every love will last. Not every 12 will be realized.
But 13 you fall short of aim(达不到目标), perhaps you can say, “Yes, but look at what I've found along the way! Look at the 14 things which have come into my life because I tried to do something!”
It is in the digging that 15 is lived. And I believe it is joy in the journey, and in the end that truly matters.
与圆
有交点,则实数
的取值范围是( )