提示词：classmates and friends ,teacher, subjects, school activities.

要求：1）短文需包含以上所有信息，可适当发挥。

      2）语句通顺，意思连贯，书写工整。

      3）文中不能出现本人的真实信息。

      4）字数要求在80左右，开头和结尾已给出，不计入总词数。

Three years' school life

    I'm a student in Grade Nine. I will leave my junior high school after I finish the exam.

   ……………………………………………………
    In a few months I have to say goodbye to my school. I feel sad about it .I love my school and all my teachers. I'll never forget my three years' school life.

已知函数$f\left(x\right)=a^x+b\left(a>0,a\ne 1\right)$ 的定义域和值域都是$-1,0$ ，则$a+b=$ ____ .

–Listen! Someone is playing ______ piano.

–Wow! What beautiful music! I like it very much

用容积相同的玻璃罩分别罩住大小、生长状况相同的天竺葵，光照相同的时间后，罩内O₂最少的是（   ）