上個月我們年級舉辦了數學競賽，許多同學也參加了競賽。
我擅長於數學，經過努力我獲了獎。老師表揚了我，同學也為我高興。
譯文：
last month there was a math contest in our grade. a lot of students joined it.
i prepared for it carefully and worked hard. i got the prize and our teacher praised me. my classmates were glad for me.