阅读下面的短文，掌握其大意，然后从短文后各题所给的A、B、C、D四个选项中，选择最佳选项。
Joe lost his arms in an accident that killed his father. Since then, he has had to depend on the 1of his younger sister Ella. In order to take care of him, Ella became his shadow, never leaving him 2 for years. Except for writing with his toes, he was completely unable to do anything in his life.
As they grew up together, they had their share of 3and they would often quarrel. Then one day, Ella wanted to separate from Joe, living 4 own life. So Joe was heart-broken and didn’t know what to do.
A 5 misfortune (不幸) struck Rosa, too. One night her mother, who suffered(受苦) from mental illness, 6. So her father went out looking for her mother. She tried to cook meals for her parents, only to overturn the kerosene light on the stove, resulting in a fire which took her hands away.
Though her elder sister Susan showed her willingness to take care of her, Rosa decided to be7 independent. And most of all she learned to do things on her own. Once she wrote the following in her composition: “I'm lucky. Though I lost my arms, I still have legs. Though my wings are broken, my heart can still 8.”
One day，Joe and Rosa were both invited to a television interview program. Joe told the TV host about his 9 future at being left on his own, while Rosa was full of hope for her life. They both were asked to write something on a piece of paper with their toes. Joe wrote：My younger sister's arms are my arms; 10 Rosa wrote: Broken wings, flying heart.
They had both stood the same sufferings, but their different 11 determined(决定) the nature of their lives. It is true that life is unpredictable. How you deal with misfortune is the true test of your character. If you choose only to complain and run away from the suffering，it will always 12 you wherever you go. But if you decide to be strong, the hardship will turn out to be a fortune on which new hopes will arise.
，在该几何体的正视图中，这条棱的投影是长为
的线段，在该几何体的侧视图与俯视图中，这条棱长的投影分别是长为
和
的线段，则
的最大值为（ ）