阅读下文，回答相关问题。

                                                                                              微妙的头发
        ①人们都有一头密密的头发，黑色的、金色的、褐色的，但很多人却只知道它与生俱来，不知道它生长的秘密、奇妙的特性、蕴含的丰富成份和非常广泛的用途。
        ②一般人有10万根头发，其生长速度为3天1毫米。人每天落发50—100根，同时又有大体相同的新发补充。头发含铜、铁、镍、钛、钼、铝、铬、锌、铅等14种元素，耐腐蚀，同等截面承受力为钢的1.25倍，200多根头发编成的辫子可吊起20吨重的物体。英国广播公司一次“创纪录”节目中，潘蒂兰小姐的一根头发竟承受了177.18克的拉力。人发拉断前可延展20%—30%，上述性能都是其它纤维难以具备的。
        ③在著名笔乡——日本广岛熊野町，头发被用以生产品种繁多的毛笔，其中最珍贵的是用新生婴儿头发制成的“胎毛笔”，每支售价一万至二万日元。设计师玛萨·海斯女士别出心裁用人发精编成各式时装，最低的售价也高达2.5万美元，有人甚至愿出百万美元高价认购其中的精品。
       ④直径仅60—70微米的每根头发，含有18种氨基酸。用毛发提取合成的精氨酸、胱氨酸已临床应用于医治肝炎及各种脱发症，组氨酸可治疗消化道溃疡，脯氨酸可治疗高血压，赖氨酸为儿童身体发育所必不可少。在捕鲸受到严格控制后，人发已日益成为生产氨基酸的重要原料。日本与印度不久前协定，在印度投资建造一座加工厂，年消耗1200吨毛发，产出80吨胱氨酸、24吨酪氨酸和1400吨含氨基酸的干粉，广泛用于制药、食品加工、化妆品和饲料工业。我国不少地区用人发作原料，制成初级产品出口创汇。
       ⑤最近几年，科学家又发现人发中含丰富的黑色素和角朊，是制造防晒油的高级原料。目前用人造原料制成的防晒油易引起皮肤过敏，而以人发为原料不仅不会造成过敏，还具有吸收紫外线光谱范围广、在强烈光照下不会变质等诸多优点。随着科学技术的发展，头发还将不断以更新的面貌，为世界提供巨大而奇妙的资源。

Zhang Lili: The most beautiful teacher in China

    Zhang Lili is a teacher at No.19 Middle School in the city of Jiamusi, Heilongjiang province. These days, many people think she is the most beautiful teacher in China, because she saved her students from a traffic accident (交通事故) on May 8, 2012.

On that day, Zhang and her two students were crossing the road outside the school gate when a bus suddenly lost control (控制) and ran fast towards them. Zhang pushed both students out of the way, but she herself was hit (被撞倒) by the bus. As a result, the 29—year—old teacher lost her legs.

The principal of No. 19 Middle School, Jiamusi City, said, "Zhang is a great teacher in our school. She’s also the most popular teacher among the students. For the students, she is like a sister. They call her Beautiful Sister. After hearing about this accident, all the students in her class cried." But Zhang is more than a teacher and sister to the 53 students in her class. She cares about their studies and even their lives.

Zhang’s bravery and kindness moved (感动) a lot of people in China. Many people visited her and sent her beautiful flowers and cards. They all hope she can get better soon and live happily for the rest of her life.