将原文由中英混杂改为全英文，并且对时态进行统一：
中国人民解放军在1949年建军，从此开始了驻守边疆的历史。8.1建军节是为了纪念这一天。如今，中国人民解放军不仅保卫着中国的国土，还在国际维和行动中发挥重要作用。
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The People's Liberation Army of China was founded in 1949, marking the beginning of its history of guarding the frontier. The 1st of August, also known as Army Day, commemorates this event. Currently, the People's Liberation Army not only safeguards China's territory but also plays a significant role in international peacekeeping operations.
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