在$△ABC$中，$A:B:C=1:2:3$，则$a:b:c=$（    ）

    A few years ago, I took a sightseeing trip to Washington, DC. I saw many of our nation's treasures, and I also saw a lot of citizens on the street—unfortunate ones, like beggars and homeless folks.

    Standing outside the Ronald Reagan Center, I heard a voice ask. “Can you help me?” When I turned around, I saw an old blind woman with her hand extended. In a natural reflex (自然反射), I reached into my pocket, pulled out all of my loose change and placed it in her hand without even looking at her. I hated being disturbed by a beggar.

    But the blind woman smiled and said: “I don't want your money. I just need help finding the post office.” In an instant, I realized what I had done. I had acted with prejudice (偏见)---I had judged another person simply for what I thought she had to be.

    I hated what I saw in myself. This incident brought back my central belief. It reminded me that I believed in being humble (卑下的), even though I'd lost that belief for a moment.

    The thing I had forgotten about myself is that I am an immigrant (移民). I left Honduras and arrived in the US at the age of 15. I started my new life with two suitcases, my brother, my sister and a strong mother. Through the years, I have been a dish washer, roofer, mechanic, cashier and pizza delivery driver, among many other humble jobs. Eventually, I became a network engineer.

    In my own life, I have experienced many acts of prejudice. I remember a time at age 17---I was busboy (餐馆工), and I heard a father tell his little boy that if he did not do well in school, he would end up like me. I have also seen the same treatment of family and friends, so I know what it's like, and I should have known better.

    But now, living my American middle-class lifestyle, it is too easy to forget my past, to forget who I am and where I have been, and to lose sight of where I want to go. The blind woman cured me of my blindness. She reminded me of my belief in being humble, and to always keep my eyes and heart open.

    By the way, I helped that lady to the post office. And in writing this essay, I hope to thank her for the priceless lesson she gave me.

阅读下列材料：

材料一：恩格斯称文艺复兴：这是一次人类从来没有经历过的最伟大的、进步的变革，是一个需要巨人——在思维能力、热情和性格方面，在多才多艺和学识渊博方面的巨人的时代。

材料二：15——17世纪，由欧洲通往印度新航路的发现、美洲的发现、环球航行的成功以及其他航海探险活动，圆满地解决了这个问题，使人类对地球的认识产生飞跃。这些事件被通称为“地理大发现”。

阅读下边一首诗，完成后面问题。
                                                                                                                                    幽居初夏 陆游
                                                                                                                  湖山胜处放翁家，槐柳阴中野径斜。
                                                                                                                  水满有时观下鹭，草深无处不鸣蛙。
                                                                                                                  箨龙已过头番笋，木笔犹开第一花。
                                                                                                                  叹息老来交旧尽，睡来谁共午瓯茶。
       注箨（zé）龙，就是笋。木笔，又名辛夷花。两者都是初夏常见之物。瓯(ōu)：杯子。