“与柏拉图为友，与亚里士多德为友，更与真理为友”，也正因为此，哈佛大学除了培养了无数杰出的哲学家，在哲学点亮的这盏精神火炬的引导下，这片盛产影响美国乃至世界发展的重要人物的园地，还培养出大量杰出的科学家和作家。由此可见（    ）

初生演替和次生演替的主要区别是（）                         

    It does not always come easy to discover oneself. From a young age, I had a strong sense of who I was to become, 1 an accident made me redefine (重审）myself.

    To me, skating was above all. There was 2 in this world that filled my heart with such joy. I spent twenty-four hours a week practicing my  3  . Having no social life or interests but skating, my devotion( 挚爱） brought me first place medals in nearly every 4.

    Unfortunately, in one show, I fell down and hurt myself 5. After several X-rays and MRI(磁共振）scans, the 6(told)me that I couldn't return to my sport any more. The pain in my back was hard to bear and even the 7 daily tasks became difficult.

    As my passion(激情）was 8, I had little sense of who I was to become. After eight months of suffering, something had to 9. Instead of wasting my days sitting around painfully, I began to put my 10 into local community service projects. By volunteering 11 a swimming teacher and summer reading assistant for kids, I got an idea of who I 12 to become. After a few months, I devoted time to my interest in the arts. Little by Little, I 13 out of the shadow( 阴影）and rebuilt my confidence.

    Sometimes, some 14 rocks block (阻碍）our way. We can choose to stay behind or try to climb over. My accident was a rock that 15 to stop me from reaching success. Today I'm a very confident and optimistic person.