中欧说，中英文的推荐信都可以接受，但是到底是中文的好还是英文的好呢？

If your recommender is an expatriate, no wonder in English. If he/she is Chinese, up to your/his/her discretion. If your recommender's English is not so good, better in Chinese.

that doesn't matter. what matters is the contents.

don't worry, language doesn't matter. Just prepare it as a normal requested application materials. My understanding, recommendation letters are not so important unless there is some amazingly outstanding stories about you.