任务型阅读

    My name is George．I'm from England．Now I'm studying in Germany．I get to school at 7：30 every morning．I find many of my schoolmates come to school by bike．  ①   

    This is an interesting thing for me．In England people usually drive，take a bus or walk somewhere，for example，to school．In Germany, I often see people，even people over eighty years old going somewhere by bike．It makes me think：  ②   

My father gives the answer．We are living in Northern Germany．It is very flat(平坦的).So it is easy for people here to go somewhere quickly by bike .And it's cheaper than(比…….便宜)going by car or by bus．Also,it's good for the environment(环境)．

    I like riding bikes now．   ③    When I go back to England，I will ride more and ask my friends to ride with me．I think they will like tiding bikes，too．

根据材料内容完成下列任务。

步骤1：选用材料相同、表面粗糙程度相同、重力不同的3个物体，用弹簧测力计测出三个物体的重力；

步骤2：把3个物体依次放在水平受力面上，用专用的仪器测出3次压力大小，实验数据见表1．

步骤3：改变受力面与水平面的倾角，用步骤2的方法，依次测出与水平面成18°角和25°角的压力大小，实验数据见表2和表3．

表1

表2

表3

请回答：

16世纪以来，世界经济出现了全新的发展态势。