下面是某同学在一次数学测验中解答的填空题，其中答对的是（　　）

阅读下面选文，完成小题。

我煨暖了，你离开的背影

吴钧尧

    ①孩子，最近，我常想起你的“四脚兽”时代。约莫十个月大时，我把你托给楼下的余妈妈照看。我把你送到她家门口，看到余妈妈摆弄了一桌子的玩具，吸引你注意。她偷偷转身，努起嘴、皱着双眉，那表情任谁看了，都知道她正催促我“走、走，赶快走”。孩子，我走得急，仿佛余妈妈的表情真的挤出声音了。

    ②我回到七楼家里，望了眼楼下中庭，你必不知道，你跟我的距离只有短短半分钟。我花了一段时间，才能把思绪转回写作计划。

    ③傍晚，我到余妈妈家接你，余妈妈正在厨房准备晚餐。我发现上午吸引你注意的玩具散落在地上，已无法提起你的兴趣。而你独自坐在客厅，灯光稀微处。你的模样和我伤心时的模样如出一辙。我轻轻敲了敲门。你看见了，先是一愣，接着，你如一头奔驰的豹，迅猛地朝我爬了过来。两只手掌，一前一后，哒哒哒地，声势与速度同等威猛。

    ④我推开虚掩的门，向前，一把将你捞起。

    ⑤孩子，我离开你之前，当然偷偷瞄你，我更好奇，若你回过头来找我，会看到我的哪一种背影？这让我想到我母亲。孩子，你渐长之后，是否会渐渐感到亲情间的某种倾斜，总是长辈费心照看晚辈，晚辈偶一回眸，长辈就感激涕零了。

    ⑥孩子，我很少与你说，我曾跟你一样，搜寻妈妈离开时的背影。一回是小时候，妈妈带我进城，探访开冰果店的堂姐。我沉溺于吃刨冰，压根忘了妈妈什么时候不在了。堂姐捉弄我说，“你妈妈不要你了。”我张皇复张皇，竟相信堂姐所言，凶猛地哭了。

    ⑦孩子，当时我相信妈妈是我的全部世界，就像你相信，我的胸膛是你永远的操场。　　

    ⑧下一回，张望妈妈背影时，我已经是“男人”了。高中毕业前，老师公开询问谁愿意提前服役，全班四、五十个人，几乎都高举着手。到了体检报到，只我一个人。虽一人，我仍独往，深信能够当个好军人。

    ⑨新兵训练，“500米障碍”是我最大的考验。它的项目有快跑、爬竿、跳壕沟、爬矮墙以及持枪匍匐前进，通过低矮的铁丝网。我虽努力，却总不能完成，最终需要加入集训。

    ⑩那段时间，每逢假日，妈妈总会舟车劳顿来受训中心看我。她带来零食，看我狼吞虎咽，是否感慨我竟饿得如此厉害？看我的体魄渐渐壮硕，对我的成长，又感到欣慰？我常想，当时妈妈的心中，必定是两难：欣喜我长大，又担忧我忘了她；高兴我能独立，又忧心我的独立，剥夺她照顾我的习惯。

    ⑪会客时间不长，我目送妈妈，走上停在操场旁的交通车。车子开动了，我仍看见妈妈，几步一回头，频频挥手，那像在说，别送了，回去吧；又像在说，别担心，妈妈跟你都会好好的。　　

    ⑫孩子，交通车离开以后，我没有回到营舍，而是回到五百米障碍场。我福至心灵般省悟到妈妈不能是永远的靠山。我独自持装备爬竿，臂力耗费殆尽，再战矮墙。我一次又一次地，面对它、冲击它、挑战它。几天后的测验，我不仅克服了，还成绩出色。当时我，气力已然耗尽，气喘连连，我望向妈妈上车的地方，淡淡地笑了，跟她说，我做到了。

    ⑬孩子，那一刻我的心情，多么像你——豹一般的“四脚兽”，快速爬向我——只是我已经站了起来，用一个儿子的独立姿态，轻轻煨暖妈妈的背影。

移动支付在给人们的生活带来方便的同时，①____。如何使其良性发展，考验着消费者的素质，更考验着②____。对消费者来说，不能只围方便，也要具有规则意识：对商家来说，不能扰乱市场秩序，把风险转嫁給社会；对管理部门来说，不能让商家陷入恶性竞争，要加强对支付平台的管理，引导买卖双方合法交易。唯有如此，③____。

笛子是通过从吹孔向管内灌气引起空气柱____ 而发声的，演奏时，通过分别开闭六个音孔，笛子就能发出____ （填“音调”、“响度”或“音色”）不同的声音。

    Soon computers and other machines will be able to remember you by looking at your eyes! The program works because everyone's eyes are different. So in the future you won't have to remember the number of your credit card when you want to use a machine or take money out of a bank. You'll just have to look at the machine and it will be able to tell who you are.

    The eye-recognition（眼睛识别）program has already been tested in shops and banks in the USA, Britain, Spain, Italy and Turkey. Soon this technology will take the place of all other ways of finding out who people are.

    Eye-recognition is a course of recognizing iris（虹膜）, which includes the following steps. First, a kind of machine needs to collect different examples of one's iris from his eyes and store them. Second, when this person goes to the bank to take out money, this machine will have iris feature extraction（采集）. Then, this machine will compare the examples kept in it with iris feature extraction. Once the examples and the feature extraction are the same, this person will be identified, and he will take out the money from the bank successfully.

    However, scientists are also working on other systems. Machines will soon be able to know you from the shape of your face or hand or even your smell! We already have machines that can tell who you are from your voice or the mark made by your finger.

    Eye-recognition is better than other kinds because your eyes don't change as you get older, and don't get dirty like hands or fingers, and even twins have different eyes. So the eye-recognition program can be up to 94% correct, depending on how good the technology is. However, some other programs may only be 51% correct now. In Britain, it was found that 91% of people who had tried it said that they liked the idea of eye-recognition.

    In the future your computer will be looking you in the eye. So smile!