下列有关物质性质的描述和该性质的应用均正确的是（　　）

阅读理解

    Last summer, as part of my high school graduation project, I volunteered at Saunders House nursing home .I choose this experience because it was something that I had never done before and I wanted to lend a helping hand．At first it was challenging because I was extremely shy. My goal in volunteering was to bring a smile to the residents（住客） by doing different activities from word games to playing chess. I feel as if I had accomplished that goal.

    At the nursing home, I did a lot of different activities with the residents ranging from Jeopardy to Wheel of Fortune. One of my favorites was a word game where I would write a ten -letter word on the board and the residents would try to come up with as many smaller words as possible. I could tell that it was one of their favorite games because they always seemed to be so enthusiastic when they played．I also transported residents to and from their rooms when they needed help; and whenever it was a nice day out, I would take them outside to get some fresh air and relax. On Saturday mornings, I would deliver the newspaper to the residents and on Sundays, I assisted with morning church services.

    The most unforgettable part of this experience was when I had one-on-one conversations with the residents. It was incredible how many great stories they had to tell. Their stories were so interesting and the experience was unforgettable for me .

一列火车

    一列火车缓慢地驶出柏林，车厢里尽是妇女和孩子。几乎看不到一个健壮的男子。在一节车厢里，坐着一位头发灰白的战时后备役老兵，坐在他身旁的是个身体虚弱而多病的老妇人，显然他在独自沉思。旅客们听到她在数着；“一、二、三——”声音盖过了车轮的“咔嚓切嚓”。停顿了一会儿，她又不时重复数起来，两个小姑娘看到这种奇特的举动，指手画脚，不假思索地嗤笑起来。一个老头狠狠地扫了她们一眼，随即车厢里平静了。

    “一，二，三——”这个神志不清的老妇人，又重复数着。两个小姑娘再次傻笑起来。这时那位灰白头发的战时后备役老兵挺了挺身板，开口了。“小姐”，他说，“当我告诉你们这位可怜的人就是我的妻子时，你们大概不会笑了。我们刚刚失去了三个儿子，他们是在战争中死去的，现在轮到我自己上前线了。在走之前，我总得把他们的母亲送往疯人院啊。”“咔嚓切嚓”……，火车依旧向前行驶着。车厢里一片寂静，静得可怕。