根据搜索结果，关于“一次难忘的旅行英语作文”的50词范文可参考以下内容：

范文一：北京之旅

Last summer, my family and I went to Beijing. We visited the Great Wall, which was amazing with mountains all around. The Forbidden City was full of old buildings and golden roofs. I took many pictures of the beautiful architecture. The trip was tiring but taught me a lot about Chinese history.

范文二：上海海滨游

On May 18, I made a trip to Shanghai. I took a bus to the sea area and saw the vast blue sea. Walking on the shore, I collected shells and enjoyed the cool water. At night, the sea scene was magical.

范文三：珠海澳门行

Last week, I traveled to Zhuhai. The city is small but beautiful with clean streets and tall buildings. I even saw cars driving across the border to Macau. The sight was magical, and I hope to visit Macau someday.

注意事项：

1. 写作时需围绕“难忘”的原因展开，如景点特色、个人感受等。2. 可结合具体旅行经历，使用生动的描述增强感染力。3. 注意语法和词汇准确性，避免拼写错误。