假定你是李华。你在美国某城市学习期间，发现所在的城市面临严重的交通拥堵。面对这种情况，你以一个留学生的名义向当地政府提出一些合理化的建议，以缓解现在的拥堵状况。词数：120左右。要点如下：

    ⑴现象：道路拥挤，车速很慢

    ⑵致因：车辆增多，设施落后

    ⑶措施：

         ①限制进入市区的车的数量,收“市区税”；

        ②修建市区停车场；

        ③多修路并改善路况；

        ④建立奖惩机制。

⑷参考词汇：市区税：congestion charge

Dear Sirs/Madam,

       Most maps of the world show lines that are not on the Earth's surface.One line is the equator(赤道)．It is an imaginary line around the widest part of the Earth.There are similar lines both north and south of the equator.These circles become smaller and smaller toward the north pole and the south pole.These lines, or circles, are parallel(平行的)—meaning that they are equally distant from each other at any point around the world.These lines show what is called latitude(纬度)．

       A navigator can know the latitude of his ship by observing the location of stars, where the sun rises in the morning and sets in the evening, and what time of year it is.With this information he knows where his ship is in relation to the north or south pole and the equator.

       Still, there is one more important piece of information necessary for safely sailing the oceans.For many centuries, scientists, astronomers and inventors searched for a way to tell longitude(经度)．The lines of longitude go the other way from latitude lines.They stretch from the north pole to the south pole, and back again in great circles of the same size.All of the lines of longitude meet at the top and bottom of the world.

       To learn longitude at any place requires knowledge about time.A navigator needs to know what time it is on his ship and also the time at another place of known longitude—at the very same moment.

       The Earth takes twenty­four hours to complete one full turn or revolution of 360 degrees.One hour marks one twenty­fourth of a turn, or fifteen degrees.So each hour's time difference between the ship and the starting point marks a ship's progress of fifteen degrees of longitude to the east or west.Those fifteen degrees of longitude mark a distance traveled.

       At the equator, where the Earth is widest, fifteen degrees stretch about one thousand six hundred kilometers.North or south of that line, however, the distance value of each degree decreases.One degree of longitude equals four minutes of time all around the world.But in measuring distance, one degree shrinks from about one hundred and nine kilometers at the equator to nothing at the north and south poles.

Notes：

①navigator n ． 领航员　②stretch v ． 伸展