情境二：小华在小学时，是个学习成绩很好的学生，可是进入初中后，随着科目增多，小华感到时间不够用，成绩有很大的下降，他父母很着急，小华也是忧心忡忡。

桂林山水甲天下。

儿童、少年如果长期不注意坐、立、行走的正确姿势，就会引起脊柱变形，这是因为他们骨的特点是（    ）

实验室中常用分解过氧化氢来简便快速的制备氧气，化学小组Ⅱ进一步探究外界条件对过氧化氢分解速率的影响，并进行了氧气性质实验．

【查阅资料】有些水果、蔬菜对过氧化氢的分解有催化作用．

    Barry Parker was a very successful businessman. He lived in a large house and drove a car. He wore expensive clothes and ate his meals in famous restaurants. His name was often in the newspaper. One day a newspaper reporter asked him, “What is the secret of your success(成功)?”
    Barry thought for a few moments and said, “I eat a special kind of fish.” “You eat a special kind of fish! What does that do?” “It makes my brain work better.” Barry said. “What kind of fish is it?” the reporter asked. “Give me fifty dollars and come back tomorrow. I'll have some for you.”
    The reporter gave Barry fifty dollars and returned the next day. “Have you got any special fish?” “Yes. Come into the house. It's in the refrigerator.”
    Barry took the reporter into his kitchen. He opened the refrigerator and took out a very small fish. “Here you are. Have this for dinner.”
The next day the reporter called on Barry again. “Did you eat the fish?” Barry asked her. “Yes, I fried it.” “Good, do you feel different today?” “No, I don't. And I think that fifty dollars was a lot to pay for such a small fish.” “Well done !” Barry said. “You see, the fish is working. You're using your brain now.”