在水藻―→小鱼―→大鱼组成的食物链中，小鱼不会吃大鱼，但大鱼可以吃小鱼，该食物链的不可逆性，说明在一个生态系统中               (　　)

    “How does the yard look?” My father asked, with his eyes shining. I could tell he was eagerly waiting for my 1 “Wonderful!” I replied after I gave it a thorough 2. Then I recited all the changed I had 3in his yard and he smiled contently.

    When I was young, my mother 4in a car accident, leaving my father alone to5their three young daughters. At the beginning, life was not always 6and my younger sisters usually complained. However, Dad always 7us to believe that life was good. Meanwhile, he tried his best to 8that belief.

    In 1972, my dad developed a piece of waste land that had been9on Okaloosa Island. Every year at the first sign of10, he would begin spending countless hours working there to make it be bursting with colors. Through his continuous hard work, the land11turned into a beautiful garden with different types of flowers and other unique plants. While our friends were enjoying their vacation through traveling to different places, we were12working with my dad in his yard, watering the flowers, weeding or cutting off the branches. Sometimes, our friends were envious of our working vacation, and we would 13them. Dad made his yard very14so that it became our vacation paradise during our childhood.

    For so many years, when we were 15, we liked to visit Dad's yard, because it could 16us of Dad's belief. It was Dad and his yard that gave us17that enabled us to survive and18major challenges in life. One day, it shocked us that Dad said he would not 19the yard. Then he explained, “Twenty years ago I decided to start my work in that yard to tell you life is good. Now my work is done.” We were sitting in 20, recalling what we had experienced. Life was good. Dad was right.

人生二维码：简单与专注

徐飞

       ①同学们，人生是一柄记忆成长的标尺：义无反顾奔向远方，留得星星点点回忆。此时此刻，我特别想问大家一个问题：怎样的人生才值得回味？

       ②我担心，“社会是个大染缸”的说法，会不会让你们倍感入世的恐慌？“拼爹胜于拼本事”的乱象，会不会让你们急着去找靠山、拉关系？一夜暴富的股市神话，会不会让你们心浮气躁？

       ③面对这些问题，“简单、专注”或许是一剂良方，这也是我给诸位的毕业礼物——人生二维码。

       ④首先，_______________。一个人对物质的实际需求，其实是有限的。因此，不要盲目攀比，要乐于并习惯于过简朴和简约的健康生活。纵然社会纷繁浮躁、物欲横流，但锦衣玉食、珠光宝气、豪宅香车，永远不应成为你们奋斗的动因，财富多寡更不应成为你们人生高度的标准。

       ⑤其次，追求人际关系的简单。A走出校门，也许你们会因人际关系的复杂学会“来事”和“勾兑”。诚然，在任何国家、任何社会，关系都客观存在。但即便如此，还是应该尽量让关系简单些、纯粹些。B希望大家坚守本色，摒弃势利，淡化功利，把宝贵的精力用在事业上。

       ⑥再次，简单起步，持续改进。在现实生活中不乏理想巨人、行动矮子之人。同学们既要志存高远，更要切实行动。2014年，全国首届“杰出工程师奖”评选，我校有3位校友荣膺该奖项。其中有一位是交通运输系1982届校友王争鸣。他在分配工作的第三天就去了现场，几乎两年没有回过单位，更没有回过家，连春节都是在勘测现场度过的。王争鸣从一名普通的外业助理工程师一步步成长为行业内尖子。他的成长故事告诉我们，再好的想法，如果不去做，一切都是白搭。

       ⑦最后，把复杂问题简单化。真理世界和认知系统中最伟大最深刻的东西，同样也是简明的、直白的，正所谓“大道至简”。因此，同学们要学会透过表象揭示事情的本来面目，穿过复杂的重重迷雾洞见现象背后简明的内在逻辑、因果关系和本质规律。

       ⑧扫一扫“简单、专注”二维码，希望你们人生从此变得“专注”。

       ⑨专注，__________。专注当然要知道专注于什么，正如打靶首先要知道靶点在哪儿一样。很多人一辈子浑浑噩噩，得过且过，还美其名曰顺其自然。他们之所以碌碌无为，很重要的一个原因是人生缺乏目标。没有目标就没有方向、没有动力，生活就将变得凌乱无序，慵懒苟且。

       ⑩专注，还要持之以恒，勤勉勤奋。实证研究和大数据表明，一个人如果要掌握一项技能，成为某一领域的才俊、专家或翘楚，一般需要练习10000个小时以上，这就是所谓的“一万小时定律”。实际上，但凡杰出成就者，他们对事业都执着专注，无怨无悔，甚或如痴如醉。

       ⑪同学们，毕业在即，请你们欣然接受这份二维码，得闲时扫一扫。