请大家帮忙看看这四句话有没有语法错误

1.Challenged the task was, but I overcame it and my ability of Java and C was significantly improved.
这句话我感觉很怪，有直接把形容词提前倒装的么？如果是我来写，我会把but去掉，challenged后加as

2.Scoring 100 plus credits in the major of Biomedical Engineering with an overall GPA of 3.66, though, but only credits of computer related courses presented me where my value lies.
这里though和but连用是什么用法呢？而且but前也没有找到主语，仅有一个状语从句
3.Looking back to my freshman semester, when I for the first time got in touch with C language on the class, after which the lecturer released an assignment to write a calendar program.
这句话应该是缺少主语把？

4.Though, ranked high prepared me a solid foundation, I have always been making the theories and practices interconnected. So an equal part of my time was paid to projects.
ranked high为什么当作主语了，如果是我我会在ranked前面加一个being

这是一家文书机构给我发的sample，我不知道是我太菜还是老师太菜，希望各位大神可以指导卤煮一下