题目内容：

英语课上，老师要求同桌同学相互修改作文。假设以下书信为你同桌所写，请你对其进行修改。文中共有10处错误，每句中最多有两处。错误涉及一个单词的增加、删除或修改。

增加：在缺词处加一个漏词符号（∧），并在此符号下面写出该加的词。

删除：把多余的词用斜线（\）划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意： 1、每处错误及其修改均仅限一词；

2、只允许修改10处，多者（从第11处起）不计分。

During the Renaissance, painters tried to paint people and nature as they real were. Rich people paid famous artists to paint pictures of them, their houses and possessions as well as their activities and achievements. One of the most important discovery during this period was how to draw things with perspective. This technique was first used by Masaccio in 1428. When people first saw his paintings, they convinced that they were looking through a hole in a wall at a real scene. If the rules of perspective have not been discovered, no one would have been able to paint such the realistic pictures. By coincidence, oil paints were also developed at this time, that made the colours used in paintings look rich and deeper. Without the new paints and the new technique, we will not be able to see the great masterpieces for which this period is famous.