timmy has decided he wants to test which if music can really flowers grow. he decides to expose some roses to classic music 10 minutes every day. he will have another group of roses that will receive no music and a third group that will get music for 20 minutes per day. timmy makes sure to have the same types of plants in each group and to expose them to music at the same time during the day. he also makes sure that all plants get the same amount of water and sunlight each day. at the end of 2 weeks, timmy measures the height of all the plants to see if the music made a difference.

identify the independent variable, dependent variable and at least 2 control variables in this experiment