题目

In the United States, 30 percent of the people have a “weight problem”. To many people the cause is obvious (明显的): they eat too much. But scientific evidence (证据) does little to support this idea. Going back to America of 1910, we find that people were thinner than today, yet they ate more food. In those days people worked harder physically, walked more, used machines much less, and didn’t watch television. Several modern studies, moreover, have shown that fatter people don’t eat more on average than thinner people. A 1979 study of 3,545 London office workers showed th（1）用数对表示图中三角形三个顶点A（，）B（，）C（，）（2）如果把三角形向右平移5格用数对表示出平移后三角形三个顶点A（，）B（，）C（，）（3）把三角形绕C点顺时针旋转90度，画出旋转后的图形．用数对表示旋转后三角形三个顶点A（，）B（，）C（，）．