下列各组数中，是勾股数的是（　　）

下列关于生命起源和生物进化的叙述中，其中不正确的是（　　）

阅读下面的文字,分别回答问题
                                                                                致网虫儿子的一封信 
亲爱的儿子：
     ①刚刚打开你的爱机给你写这封信的时候，你设置的开机问候真是吓了我一大跳，那低沉的一声“哈罗”让我忽然意识到，你已经是个大男孩了。
     ②真的，转眼间你已经16岁了，不再是那个像“附件”一样跟着我的小男孩，已经到了具有逆反心理的年龄，这就使得我们之间越来越无法“兼容”，冲突也越来越多。记得对我以前给你下达命令时，你的运行速度不亚于当今的P4处理器。可现在哪怕是让你倒个垃圾这样的小事，你都不大情愿，有时候我还得敲几次“回车”你才执行；遇到你不高兴的时候，就干脆“死机”——根本不理我。
     ③有时逼你吃饭，我是怕你“系统”资源不足，“主板”受损。尽管你已经瘦得像一根“内存条”，你却毫不领情。看着你漫不经心地吃着饭菜，我恨不得在碗里“剪切”了，直接往你嘴里“粘贴”！
     ④自从买了电脑回来，你的眼里就只有它，只要在家，你都是坐在电脑前。我担心你在电脑前坐久了会过早地“安装”上“视保屏”，担心影响你的学习，更担心你被网上的“病毒”传染，为此，我限制了你的上网时间。你却对我说，我对你的这一套“操作系统”版本太旧，需要“升级”。
     ⑤前天的家长会上，你们班主任说你的成绩明显下降，还说了你在学校的种种“非法操作”。比如作业没做好就顺手将同学的作业“复制”一份，上课时用小纸条给MM“发送”信息（还画个小企鹅）……
     ⑥我承认你在电脑方面有天赋，小小年纪就通过了省计算机中级考试。可是现在你不打好文化基础，将来还是会被社会“删除”的。
     ⑦有时候我觉得我们之间有些陌生，因为我越来越看不懂你了。在我的眼里，你有时像加了密的文件，而我忘记了密码；有时像幅不知什么格式的图片，没有合适的看图工具打开它；更多的时候，你像一堆乱码，我看不懂，解不开。
     ⑧说实话，我并不想改变你原有的“界面”，也不愿每天挂着个“黑屏”的脸面对你，更不愿“压缩”你的个性，只想用我的爱为你筑起一堵抵御侵袭的“防火墙”。亲爱的儿子，你能理解做母亲的这颗心吗？因为从你来到这个世界的那天起，我就中了“I love you”病毒，无药可救了。
     ⑨好了，今天就聊这么多。我不想做你威严的母亲，就当我是你的一个无话不谈的朋友。希望这封信对你有所帮助，还请你用“磁盘扫描”程序检查一下“系统”中的错误，用“杀毒软件”杀一下毒，或者干脆重装一下“系统”，那样运行起来会更快，更好！
     ⑩祝你重装成功！

  爱你的母亲
×年×月×日

    It is not easy getting the attention of tourists away from the well-known white sandy beaches of Byron Bay. But in this relying Australian surf town, a solar (太阳能的)-powered train might just do a good job.

    Opening to the public in December 2017 along a 1.9-mile-long stretch (一段) of track that sat abandoned for more than a decade, the Byron Bay Rail Company has breathed new life into a pair of disused railcars dating back to the 1940s. They're now used to transport passengers between Byron Bay's central business district and the North Beach area. After remaining in service as part of a regional passenger rail network until the early 1990s, the aging railcars were out of service and sat uncared for — almost destroyed by time and unpleasant Aussie climate — in a railyard for more than 20 years. You'd never know it by looking at these nearly 70-year-old workhorses today, though: they've been decorated, equipped, topped with custom-made photovoltaic panels (定制的光电池板) and rearranged to accommodate up to 100 seated beach goers.

    It's those train-top PV panels that truly set the Byron Bay Rail Company's flagship train apart from other heritage rail restoration projects.

    Drawing additional power from a 30-kilowatt solar array (阵列) located atop the train's storage building, the tain is said to be the first in the world to be completely powered by the sun. Solar energy caught by the 6.5-kilowatt train-top solar panels is stored directly in an onboard battery system that powers motors, lighting and the like. When stopped at its home platform, the train pushes into chargers for quick battery top-offs with electricity produced by the storage building's rooftop solar array. The 77 kilowatt-hour battery can hold enough juice for 12 to 15 runs on a single charge. During long periods of cloudiness when the solar arrays don't get enough sun, the train uses the main electric network, supply using renewable energy sold by community-based service Enova Energy.

    The Byron Bay Rail Company's first-in-the-world folly solar-powered train is a good example of historic rail preservation with a 21^st century development. Operating as a not-for-profit company, the Byron Bay Rail Company also expected the AU$4 million line to be a way to relieve traffic jam between downtown Byron Bay and the rapidly growing North Beach area. Really, there's no bigger unpleasant thing than sitting in bad traffic for 40 minutes trying to get to the beach.

I____  ____ a new bike.