一篇英语小作文
假设你是Mary,你们班做了一个实验,你现在写信给你的朋友 Jenny这是个有趣的实验
提示：
What do you need:two green plants,a dark box
How to do it :plant one plant in the dark box,another in the garden
Result:after about a week,the one in the dark box becomes yellow,but the one in the garden is still green
Conclusion :plants need oxygen to grow.