假定英语课上英语老师要求同桌之间互相修改作文，请你修改你同桌的以下作文。
文中共有10处语言错误，每句中最多有两处。错误涉及一个单词的增加、删除或修改。
删除：把多余的词用斜线（\）划掉。
增加：在缺词处加一个漏字符号（∧），并在该词下面写出该加的词。
修改：在错的词下划一横线，在该词下面写出修改后的词。
注意：1）每处错误及修改均仅限一词。
2）只允许修改10处，多者（从11处起）不计分。
One day a girl found a dead rat in front of her door. This kind of thing happens a lot of in the city during winter, but she didn’t pay much attention to it. However, the next day it was a dead bird on the doorstep of its house. She thought it was just some jokes playing by those naughty kids. But the same thing happens for a week! She started to get angrily. So she set up a hidden camera on the door, tried to find out the truth, which really gave her big surprise. The criminal was a cat! It left those dead body in front of her house every day at midnight.
羊一定能产生aY的精子
豌豆（Dd）产生雌雄配子数量及比例为D：d=1：1
