材料一：2012年11月2日，江苏扬州扬大附中学生徐砺寒在骑车上学途中不慎剐蹭到一辆路边的轿车。他在原地等了半小时没等到车主，就留了一张字条：“我是扬大附中一名学生，在今天中午的放学途中不小心弄坏了您的车。主要是一划痕及左后视镜。我无法及时赔偿，对不起。”并在字条上留下了联系方式。车主看后很感动，没有要求孩子赔偿。

       材料二：2012年7月26日，沈阳出现暴雨预警。沈阳铁西公安微博发起避雨、送伞和送热水的“雨中情”行动，受到了博友和市民的积极回应。随后大雨中，10把雨伞都被市民借走，雨停后却收回了12把。原来，在最开始借伞的4人中，有一人在还伞时，还将自家的两把雨伞送给了铁西公安局，希望尽绵薄之力，向更多的人传递心中那份温暖。

       材料三：正能量是指一切予人向上和希望、鼓舞人不断追求、让生活变得圆满幸福的动力、感情……

读下图，请回答。

A true friend is always helpful. I didn’t believe it 1 one thing happened to me when I was in Grade 7.
Li Jie was one of my classmates. He and I were also neighbours. He always listened to his mother 2 I didn’t like listening to my mother. I didn’t think it was necessary for 3 to teach me anything. Li Jie knew all about that but he said4 to me.
One weekend, Li Jie invited me to watch a film. I liked films very much so I went to the 5 with him happily. The film was about the love between a6 and her son. After watching it, I began to know how great the love of the mother was. I felt 7 that I didn’t listen to my mother before. I decided to think more about my mother than about8. After I told that to him, Li Jie smiled and said, “It’s really necessary for you to watch such a film. That was a good choice (选择) for both you and me.”
Suddenly, I knew9 he invited me to watch the film. Just at that time, I knew a true friend is always 10.

生物化学分析得知，人体体液中的钠离子、钾离子、钙离子、镁离子、氯离子等无机盐离子的比例跟海水中相应无机盐离子的比例接近．这个事实证明（　　）