A school principle wants to observe if natural light has an effect in the classroom learning. The principle randomly chooses two groups of students of the same age and grade, and places both groups in rooms on opposite sides of the school, one facing east and one facing west, during a 10am class. The test scores of both classes are compared at the end of the semester. How could this observation be changed into a valid experiment of the effects of natural light?
A. by introducing adjustable light fixtures in each classroom
B. by tinting the windows in both classrooms
C. by including classrooms facing north and south
D. by introducing adjustable blinds in each classrooms

the most boring ever written

step-by-step explanation:

i am writing something. yes, i plan to make it the most boring thing ever written. i go to the store. a car is parked. many cars are parked or moving. some are blue. some are tan. they have windows. in the store, there are items for sale. these include such things as soap, detergent, magazines, and lettuce. you can enhance your life with these products. soap can be used for bathing, be it in a bathtub or in a shower. apply the soap to your body and rinse. detergent is used to wash clothes. place your dirty clothes into a washing machine and add some detergent as directed on the box. select the appropriate settings on your washing machine and you should be ready to begin. magazines are stapled reading material made with glossy paper, and they cover a wide variety of topics, ranging from news and politics to business and stock market information. some magazines are concerned with more recreational topics, like sports card collecting or different kinds of hairstyles. lettuce is a vegetable.