欢迎欢迎，多多来发贴哦。
整体还是不错的，有一些地方，特别是运用连词的时候，更流畅些更好。
如果你放了我，将来你在大海里一旦遇到危险，我保证会去帮你。
汉威尔一边往安全的山顶上爬一边开心地说。
这两句有点拗口。
1. Once upon a time, there was a fisherman called Hywel. As he sat on the rocks one day, he saw a mermaid in the distance. Hywel had never seen anyone so beautiful in his entire life.
从前，有个渔夫叫汉威尔。一天，他坐在岩石上，看到远处有一条美人鱼。汉威尔这辈子还从来没见过谁长得这么漂亮。
2. Quietly, Hywel crept up to the mermaid. She had very long hair, which she combed as she sang a pretty song. Her name was Modlen. She didn’t notice Hywel at all. "I must take her home," he thought.
汉威尔轻轻地、蹑手蹑脚地靠近美人鱼。美人鱼一边唱着美妙的歌，一边梳着长长的秀发。她的名字叫莫伦。莫伦根本没发现汉威尔。“我要把她带回家。”汉威尔想。
3. Hywel tiptoed along the path and quickly picked up the mermaid in his arms and ran away with her to his boat. The mermaid cried and cried, "Let me go! Please, let me go!" But Hywel shook his head.
汉威尔踮起脚尖，快速地抱起莫伦，跑向他的小船。莫伦不停地大哭：“放开我！请放开我！”但是，汉威尔只是摇头。
4. Hywel took the mermaid home. He looked after her with food and water but she cried day and night. Hywel’s friend Maredudd told him to let her go back with the next tide.
汉威尔把莫伦带到家里，他拿东西给她吃，拿水给她喝，可是莫伦还是昼夜不停地哭。汉威尔的朋友马瑞德劝他下次涨潮的时候就放了莫伦。
5. But Hywel just thought that Maredudd was jealous. "She’ll cast a spell on you if you don’t let her go," Maredudd warned him.
但汉威尔觉得马瑞德是嫉妒自己。“如果你不放了她，她会施加魔法诅咒你的！”马瑞德警告道。
6. As time went by, the mermaid began to look thin and pale. "Oh Hywel, please let me go home," she pleaded. "If you let me go, then I promise I will come and help you if you are ever in danger at sea."
随着日子一天天流逝，美人鱼开始日渐苍白和消瘦。“哦，汉威尔，请放我回家吧。”她恳求道，“如果你放了我，将来你在大海里一旦遇到危险，我保证会去帮你。”
7. Remembering his friend’s warning, Hywel agreed to let her go. He carried her to the shore and kissed her goodbye. "I will call your name three times if ever you are in danger," promised Modlen.
汉威尔想起朋友的警告，同意了。他带着莫伦来到岸边，和她吻别。“一旦你遇到危险，我就叫三声你的名字。”莫伦向汉威尔保证道。
8. Many years passed by, but Hywel never forgot about Modlen. Then one evening when he was out fishing, Modlen appeared. "Hywel, Hywel, Hywel! Draw your net!" she cried.
许多年过去了，但是汉威尔一直没有忘记莫伦。一天晚上，当他正在出海打渔，莫伦出现了：“汉威尔！汉威尔！汉威尔！快收网！”她叫道。
9. The sea was calm and there were no storm clouds to be seen in the sky. All the other fishermen laughed at Hywel as he rowed back to shore.
这时的海面很平静，天空也看不到一点乌云。当汉威尔把船划向岸边的时候，其他的渔夫都在嘲笑他。
10. But, suddenly a big storm started. The rain started to pour down and great waves rose up. “I owe my life to Modlen the mermaid,” said Hywel happily as he climbed the hill to safety.
但是，突然暴风雨来了，大雨倾盆而下，海面上掀起了巨浪。“美人鱼莫伦救了我的命。”汉威尔一边往安全的山顶上爬一边开心地说。
这是刚刚从BBC上看到的一篇，忍不住贴上来，水平实在有限，请大家批评指正，谢谢！
搜狐的图片不能上传，郁闷！