NEED ANSWER ASAP!!!
15 POINTS!!!!
A student investigating how experimental conditions affect plant growth grows two identical plants, one indoors and one outdoors. Three month later the plant grown indoors was 6 cm tall, and the plant grown outdoors was 18cm tall.
Part A: Identity one variable, other than light, that the student should have controlled in this experiment.
Part B: Explain why variables should be controlled in experiments