The weather was hot应该改成：It was hot.
Our school startsat eight thirty.应该改成：Our class started at eight thirty.
I'm happy应该改成：I was happy.
Because the match lesson(数学课）and art lesson so fun.应该改成：Because the match lesson(数学课）and art lesson are so funny.
I'm excited.应该改成：I was excited.
Because my school held（举办）gymkhana（运动会）.应该改成：Because the gymkhana was held in my school.
So,I hope this day and today was great day!应该改成：So,I wish today a great day!