Humans are much worse at estimating risk than we think we are. While we overestimate the risk of rare but disastrous occurrences, such as being attacked by a shark, many of us seriously underestimate the risk of behaviors that reduce our lifespan (寿命), such as smoking.

    In fact, there are two types of risks — acute and chronic. Acute risks are those that may kill you immediately, such as a car accident.

    Chronic risks don't kill you immediately but rob you of your life a little at a time. If you choose to eat an unhealthy diet, for instance, you may appear to be getting away with this, but you risk developing illnesses in future that may shorten your life.

    The problem is we value things much less when they occur in the future. Distant events are abstract — we don't know how and when they might affect us -~ so we care less about them.

    Take smoking for example. It is just about the worst choice you can make for your health. Every two cigarettes that you smoke takes 30 minutes off your lifespan.

    In contrast, eating vegetables is clearly very good for you, with each serve increasing your lifespan by two hours. This is a massive health gain and clearly should be a strong motivator for you to eat healthily.

    Drinking coffee is also good for you, though with limited health gains. Each cup of coffee (assuming you drink reasonably), is associated with approximately a ten-minute gain in your lifespan.

    Even drinking alcohol may add to your lifespan, with each serve adding 30 minutes to the length of your life. But this health gain is only true for the first drink; following drinks shorten lifespan. Alcohol also causes an acute risk when consumed in excess. Too much drinking gives you a 25 in one million chance of sudden death.

    We shouldn't be too nervous about exposure to risks. Life is all about making decisions about risks and rewards, and we all have a different starting point for what we consider acceptable risks to take. Even if we don't always make the healthiest decisions, at least we can make ones that are fully informed.

阅读下面的材料，根据要求写一篇不少于800字的文章。

    厦门大学94岁高龄教授潘懋元，用79年执着于一件事，研究高等教育学，开创中国高等教育学科之先河；

    某大学生热衷于参加选秀节目，渴望一夜走红，登上人生巅峰；

    更有一种人羡慕“官二代”“富二代”，坐享其成……

    对于这三种人，你怎么看？请你结合材料内容和含意作文，表明你的态度，阐述你的看法，体现你的思考、权衡和选择。

    要求：选好角度，确定立意，明确文体，自拟标题，不要套作，不得抄袭。

    圆珠笔头分为笔尖上的球珠和球座体。油性圆珠笔头的圆珠由黄铜、钢或者碳化钨制成；水性圆珠笔头的圆珠则采用不锈钢、硬质合金或氧化铝等材料制成。由这些材料制成的圆珠笔，要满足在同一个角度下，连续不断地书写800米且不出现断线的情况才算合格。

    生产过程中，碳化钨先被制成比标准尺寸略大的小颗粒，散铺在一个带沟槽的板上，并使这些小颗粒进入圆形沟槽，仅露出其顶部。然后放上一块又重又平的顶盘，压在这些小颗粒上面，在两盘之间注入研磨油，使这些小颗粒浸泡在含有粉末状金刚石的润滑混合物中。

    接着转动下盘，使这些碳化钨小颗粒在圆形槽内不断地翻腾滚动，在槽壁、顶盘以及相互之间不断地接触，金刚石粉末不断地把这些小颗粒的边角研磨掉，使它们逐渐变得又圆又光。研磨过程还要停下来几次，将这些小圆珠取出洗净，进行测试，直到生产出光滑度适中、符合标准的小圆球为止。

    小圆球太光滑了就粘不上墨汁,也就不能写字。生产一颗碳化钨的小圆珠笔珠大约需要断断续续地研磨几十个小时。这一过程真正的难点在于怎样把极大数量的小圆球,做到尺寸相同的。这里的高精度、高互换性是基于整个工业体系的严谨才能得到的。

    直径仅有2.3毫米的球座体，无论是生产设备还是原材料，此前都长期掌握在瑞士、日本等国家手中。球座关键部位的尺寸精度要求在两微米之内，表面粗糙度要求为0.4微米，在笔头最顶端的地方，厚度仅有0.3毫米到0.4毫米。由于后期要进行高精度的加工，既要容易切削，加工时又不能开裂，对不锈钢原材料提出了极高的性能要求。

    加工球座体专用到的机床,是专用于加工镍白铜和不锈钢水性、中性圆珠笔头的自动加工机床,将冲成一定长度的坯料加入料斗后,机床能自动完成从进料夹紧,分多次钻削内孔、车外圆、锥面、镗珠座孔、冲气槽、装球珠、收口、压珠直至出料,加工装配全过程。

    圆珠笔头对加工精度的要求极高，由于笔头上不仅有小球珠，里面还有5条引导墨水的沟槽，生产加工中一个小小的偏差都会影响书写的流畅度和笔的使用寿命，笔尖的开口厚度不到0.1毫米，还要考虑到书写角度和压力，球珠与笔头、墨水沟槽位必须搭配得“天衣无缝”，加工误差不能超过0.003毫米。

    为了给数百亿支圆珠笔安上中国笔头,国家早在2011年就开启了这一重点项目的攻关。没有可借鉴的资料，成分的配比都是从几十公斤开始炼……为找到国外守口如瓶的保密配方,科研团队重在摸清笔尖钢的成分配比这一环节,在切削性和加工性上寻求平衡点,最终在笔头用不锈钢材料的7大类工艺难题上取得突破。2017年1月10日,太钢正式对外宣布,成功研发“笔尖钢”,百亿支圆珠笔有望安上“中国笔头”。