一辆汽车牵引力是4× 10³N，行驶10km消耗3kg汽油，这辆汽车的效率是多少? 已知汽油的热值q=4.6×10⁷J／kg。

最近，小明家里的电灯经常忽明忽暗．小明从学校借来实验仪器，想通过实验来研究产生这种现象的原因．

下列各句中，没有语病的一句是(　　)

根据短文理解，从A、B、C、D四个选项中选择最佳答案填空。

    At age 14, 15 and 16, the way we looked was the most important thing in the world to us. My friends and I wanted nothing less than perfection.

    In high school, we joined the gymnastics team, and our 1 became even more important to us. We had no fat, only muscle. On the weekends, we would go to the beach,  2 of our flat stomachs.

    One summer day, all my friends were at my house 3. At one point, I was running back to the pool. I 4 on a bee, and while it was dying under my foot, it stung (蛰) me. I instantly started to feel 5. That night, I began to run a high fever and my leg and foot were red, hot and swollen. I couldn't walk. I could barely 6.

    When my foot started to go numb, everyone became more 7. My foot was not getting enough blood. I had to go to the hospital, and my leg 8 as if it were badly broken. I couldn't move. All I could do was think about how soft my middle was becoming. That  9 me more than any concern over my leg.

    That would all 10 when I heard the doctors mention possibly cutting off my foot. It was still not getting the 11 supply it needed. The doctors would have to speed up their treatment.

    Never before did I have such great 12 for my foot. And walking seemed like a 13 from the gods. Less and less I wanted to hear my friends talk about 14 and who was wearing what. More and more I expected visits from other kids in the hospital, who were quickly becoming my friends.

    One girl came to visit me 15. Every time she came, she brought flowers. She was recovering from cancer and felt she should come back and 16 the other patients.

    She still had no hair, and she was swollen from the medications she had been taking. I would not have given this girl a second 17 before. I now loved every inch of her and looked forward to her 18.

    Finally, I was improving and soon I went home. My leg was still swollen, 19 I was walking, and I had my foot! When I would go back to the hospital, I often saw my friend. She was still visiting people and 20 good cheer. I thought if there was an angel on this earth, it had to be her.

阅读下面的文字，完成下列各题。

中国的爱因斯坦——束星北

张再生

    上世纪80年代的一个春天，海滨某军港，一派严肃、紧张的气氛。原来这里正在进行航天事业的一项重要试验：卫星回收工程。按照测算，卫星将于2分钟后落入眼前的水域。人们一个个屏住呼吸，两眼直瞪着蔚蓝的天空。2分钟后，“飞物”突然从天而降，落入大海，水柱冲天。快艇迅速劈波斩浪，去迎接这“天外来客”。顿时，岸上、船上的官兵和群众情不自禁地又跳又叫，欢声雷动。

    在这激动人心的时刻，人们不会忘记为了测算卫星落点而熬过许多不眠之夜的首功之臣束星北教授。

    束星北出生于江苏邗江。其父束日璐曾是南通张謇实业集团的知名人士。束星北自幼聪明好学，才智过人，童年入私塾，深得秀才老夫子魏楚翘钟爱。1924年束星北以优良成绩考取三江大学。两年后又远渡重洋，入美国拜克大学读书。身在异邦，束星北克勤克俭，矢志苦读．当时，他父亲是实业巨子，生母家是江都望族，可他却谢绝长辈们的经济资助，搬住在美国三藩市同乡会馆内，与工人们一道参加体力劳动，挣得收入以支付学费。

    束星北畅游在浩瀚的知识海洋中。1929年，他对爱因斯坦相对论产生了强烈的兴趣。几近一年，他屏绝人事，埋首书斋。智慧之树骤然开放出奇葩——研究“相对论”的两篇论文脱稿了。探索神秘未知世界的热望，化开了层层坚冰，“四维时空”的科学课题又如一盏神灯在远方闪烁，引导他走向新的境界，去寻找当代物理大师爱因斯坦。

    此时的爱因斯坦已是如日中天，蜚声全球。他身材矮小，仪容和蔼。对于这个来自东亚的门徒，他一见如故。他们通宵达旦畅谈，大师赞誉了束星北的两篇论文。不久，大师从柏林大学替束星北争得经费，物理界的巨星和新星合作了。作为大科学家爱因斯坦的助手，束星北工作一年，进步更快，造诣更深，硕果累累，从多方面发展了“相对论”。更大收益是，束星北继承了大师“自由平等讨论的波尔学风”。由于希特勒排犹之风日盛，爱因斯坦被迫离德，束星北经大师安排，于1929年10月转到剑桥大学、爱丁堡大学继续研究，在天体物理方面颇有创见，获博士学位。1930年登上美国著名的麻省理工大学的讲台，开始了他漫长的物理学教学生涯。

    身为海外学人的束星北，一直萦怀祖国。1931年“九•一八”事变以后，他毅然辞聘而归，准备投笔从戎，抗日救国。回国后，束星北被浙江大学慕名求聘，请他与王淦昌教授共同研究“衰变”这一尖端课题。

    在浙大，束星北誉满校园。他开的课，学生爱听，教师也争相入座，他不照课本宣讲，而是联系实际，深入浅出。乍听似乎无章，细加揣摩却句句有着。他认为，物理学是一门很美的科学，大至宇宙、小至基本粒子，都是研究的对象，寻求其中规律，这是十分有趣的。天性率真的束星北有时跳上讲台，有时坐在椅背上，大发宏论，侃侃而谈，一条腿还下意识地晃动着。课堂上，一旦哪位学生指出他的疏漏之处，他便肃然静坐，恭听学生发言．每当学生讲出新的见解，束星北就会情不自禁地捶他一拳，连呼：“妙！”就是这种“波尔”学风，造就了一批物理人才。其中最负盛誉的便是后来的诺贝尔奖获得者李政道教授。当年，束星北特别器重这位学生。李政道一度想辍学参军，是束星北切意挽留；李政道因车祸伤腿，束星北又特意把他接到重庆，精心安排治疗调养。难怪，数十年后，李政道仍念念不忘乃师之恩，曾致书问候：“我物理的基础……成就归源，都是受先生之益。”

    当五星红旗在天安门升起的时候，束星北教授心潮澎湃。他夜以继日，勤奋科研。1952年到山东大学任物理系教授，除了正常教学研究外，还兼研气象学，曾在《中国气象学报》上发表多篇具有灼见的文章，成了竺可桢、赵如章的好朋友，被聘到中国气象学会青岛研究所负责科研。1980年，他又为航天工业的卫星回收试验立下了赫赫功劳。直到他生命最后一息，还在指导他的学生做“海洋内波研究”。

    一代大物理学家束星北离开了我们，但他的英名却永载史册。诚如其学生李政道的唁函所说：束老师是中国物理学界的老前辈，国际闻名，桃李满天下……