麻烦大家帮我翻译一下这些汉译英，英译汉，好的加分！不要中文式英文！

1.They had arrived the station 20 minutes before the train did.
2.There are signs that this accident could have been completely avoided.
3.He is a history major.
4.There are only two course availbale.
5.He devoted all his life to benefitting the humankind.
6.我交了一个叫罗伯特·威尔逊的朋友，他是一个加拿大学生。
7.像班里一半的同学那样，我的大学开销部分来自奖学金。
8.我哥哥主修哲学。
9.他是一个有责任感的医生，他很享受病人对他（医术）的信任。
10.你喜欢昨天的音乐会么？

（楼上有句子理解不正确……）

1. They arrived at the station 20 minutes before the train arrived.
2. Evidences show that the incident is avoidable.
3. He is a history major.
4. There are only 2 courses for you to choose.
5. He has dedicated his life to the happiness of human beings.
6. 我和一位加拿大tongue交朋友了，他叫罗伯特威尔森。
7. 和我一半的同学一样，我获得了一份半奖奖学金。
8. 我哥哥/弟弟的专业是心理学。
9. 他是一个负责人的医生，喜欢的病人身上体现出的信心。
10. 昨天的音乐会听的开心吗？