英语翻译
问题描述：
英语翻译
（二）
The building of the Great Wall first began during the period of the Warring States（476-221 BC）.
After that,walls were built by different kingdoms to protect their countries.
In 221 BC after the first Emperor of the Qin Dynasty unified China,he decided to have the walls linked up and extended.
答
长城最早始建于美国内战期间（公元前476-221）
后来,由不同的国家为保其王国而建.公元前221年,第一位清代皇帝统一中国以后,他决定将各长城连接并延长.