番茄是重要的园艺作物，为了研究番茄植物的生理现象，有同学做了如下实验：在透明密闭的小室内，放置两个培养罐，分别存放植物培养液和二氧化碳缓冲液（二氧化碳缓冲液可以使室内二氧化碳的量保持恒定），如装置图1．调节灯的光照强度，根据毛细管内水柱左右移动情况，绘制图2．此实验不考虑温度等因素对小室内气体体积的影响．

I hear             .

根据短文内容，完成下列各题。

    In China, September 10th is a special day. It's Teachers' Day. Teachers' Day began in 1985. It is a great day for all the teachers and also a happy time for us students. How do we spend Teachers’ Day every year?

    On that day, we go to school early in the morning, and put a bunch (束) of flowers on our teacher's desk to give him or her a big surprise. Some of us help him or her to do some easy work. And others stand at the school gate to say hello to teachers when they go into the school.

    In the afternoon, we have a party. We sing and dance with the teachers.

    All of us are very happy. The teachers say that the best reward (奖励，奖赏) for them is to see our great progress(进步).

用化学符号填空：