根据短文内容，从短文后的选项中选出能填入空白处的最佳选项，并在答题卡上将该项涂黑。选项中有两项为多余选项。

    All around the world, people are working hard to make their cities safer and more pleasant for pedestrians (行人). Cities havepainted crosswalks on their streets, made streets narrower, put in traffic lights and speed bumps (减速带) and madeplans to help more kids walk or bike to school.

    Many people have learned from a man from Brisbane, Australia,named David Engwicht. His book Reclaiming Our Cities and Towns has a simplemessage____. Kids playedthere, and neighbors stopped there to talk.

    But now, streets are just for cars and trucks. People stay inside to get away from the noise and dangerous traffic, and we lose contact with our neighbors____.  People needto take back their streets. Engwicht travels around the world, helping people think differently about pedestrians, streets, and neighborhoods.____． He has workedin neighborhoods from Honolulu to Scotland.

    While Engwicht was writing his book, he learned how neighbors in the city of Delft, in the Netherlands, stopped dangerous traffic on their street. They put old couches, tables, and planters in the street.____. When the police arrived, they saw how these illegal actions made the streets safer. Soon city officials started planning ways to make cars slow down, and“calm”thetraffic.

    Engwicht says we should think about streets as our “outdoor living room”.____．

    In the future, streets will be safe places for children again,and our neighbors will become our friends.

a. Cars and pedestrians crowded the street.

b. Calming the traffic is just the beginning.

c. Cars could still pass, but they had to drive slowly.

d. He says that in the past, streets belonged to everybody.

e. It's hard to take measures to solve the traffic problems.

f. Besides his books and articles, he gives many speeches.

g..  Engwicht says that we should use streets for more than just transportation.

中国石拱桥

       ①石拱桥，桥洞成弧形，就像虹。古人神话说，雨后彩虹是“人间天上的桥”，通过彩虹就能上天。我国的诗人爱把拱桥比作虹，说拱桥是“卧虹”“飞虹”等。

       ②石拱桥在世界桥梁史上出现得比较早。这种桥不但形式优美，而且结构坚固，能几十年几百年甚至上千年雄跨在江河之上，发挥交通作用。

       ③我国的石拱桥有悠久的历史。《水经注》里提到的“旅人桥”，大约建成于公元282年，可能是有记载的最早的石拱桥了。我国的石拱桥几乎到处都有。这些桥大小不一，形式多样，有许多是惊人的杰作。其中最著名的当推河北省赵县的赵州桥，还有北京附近的卢沟桥。

       ④赵州桥横跨在洨河上，是世界著名的古代石拱桥，也是造成后一直使用到现在的最古的石桥。这座桥修建于公元605年左右，到现在已经1300多年了，还保持着原来的雄姿。到解放的时候，桥身有些残损了，在人民政府的领导下，经过彻底整修，这座古桥又恢复了青春。

       ⑤赵州桥非常雄伟，全长50．82米，两端宽9．6米，中部略窄，宽9米。桥的设计完全合乎科学原理，施工技术更是巧妙绝伦。唐朝的张嘉贞说它“制造奇特，人不知其所以为”。这座桥的特点是：（一）全桥只有一个大拱，长达37．4米，在当时可算是世界上最长的石拱。桥洞不是普通半圆形，而是像一张弓，因而大拱上面的道路没有陡坡，便于车马上下。（二）大拱的两肩上，各有两个小拱。这个创造性的设计，不但节约了石料，减轻了桥身的重量，而且在河水暴涨的时候，还可以增加桥洞的过水量，减轻洪水对桥身的冲击。同时拱上加拱，桥身也更美观。（三）大拱由28道拱圈拼成，就像这么多同样形状的弓合拢在一起，做成一个弧形的桥洞。每道拱圈都能独立支撑上面的重量，一道坏了，其他各道不致受到影响。（四）全桥结构匀称，和四周景色配合得十分和谐；就连桥上的石栏石板也雕刻得古朴美观。唐朝的张鷟说，远望这座桥就像“初月出云，长虹饮涧”。赵州桥高度的技术水平和不朽的艺术价值，充分显示了我国劳动人民的智慧和力量。桥的主要设计者李春就是一位杰出的工匠，在桥头的碑文里还刻着他的名字。

关于的方程有一个根为1，则此三角形为(  )

15÷3=5