用最高级形式写的关于骑车上学的英语作文50字加翻译

In the morning,I rode the highest bike in my house to school.That was the hardest thing I have ever done.However,I rode it in the fastest speed because I was running out of time.Unfortunately,though I rode the highest bike in the fastest speed,I was the latest students who came in the classroom.
在早上,我骑着我家最高的一辆单车上学.那是我最难做的一件事.不过,我仍然骑得很快因为我快没有时间了.不幸的是,我果然是最后一个进入教室的学生.

什么是最高级形式？像 tall－tallest 吗？