化合物丙可由如下反应得到：C₄H₁₀O C₄H₈ ，丙的结构简式不可能是(　　)

根据短文理解，从A、B、C、D四个选项中选择最佳答案填空。    

    When I was 13 years old, a boy gave me an important gift. It was a 1. It was the early autumn of my first year at a junior high school and my old school was far away. 2, no one knew who I was. I was very lonely and afraid to make friends with 3.

    Every time I heard the other students talking and laughing. I 4 my heart break. I couldn't talk to anyone about my problems, and I didn't want my parents to 5 me. Then one day, my classmates talked happily with their friends, but I sat at my desk 6 as usual. At that moment, a boy entered the classroom. I didn't know who he was. He passed me and then turned back. He 7 me and without a word, smiled.

    Suddenly I felt the touch of something bright and friendly. It  8 me feel happily, lively and warm. That smile changed my life. I started to talk with the other students and made friends. Day by day, I became closer to everyone in my class. The boy with the lucky smile 9 my best friend now.

    I believe that the world is what you think it is. If you think you are lonely, you might always be alone. So smile at the world and it will 10.

    世有伯乐，然后有千里马。千里马常有，而伯乐不常有。故虽有名马，祗辱于奴隶人之手，骈死于槽枥之间，不以千里称也。

    马之千里者，一食或尽粟一石。食马者不知其能千里而食也。是马也，虽有千里之能，食不饱，力不足，才美不外见，且欲与常马等不可得，安求其能千里也？

    策之不以其道，食之不能尽其材，鸣之而不能通其意，执策而临之，曰：“天下无马！”呜呼！其真无马邪？其真不知马也！

图是某发达国家与某发展中国家人均GDP和人口密度示意图。下列工业中，最可能由甲国转移至乙国的是（　）