What structure changes its shape to focus light at the back of the eye?

A BMI of below 25 is considered normal; a BMI of above 25 is considered ______; a BMI of 30 or more is considered ______; and a BMI of 40 or more is considered ______

Fill in the blank with correct word

An administrator believes that the placement of motivational posters on the walls in classrooms of academic buildings will lead to increased GPAs (grade point averages) at his school

To test his theory, he randomly assigns certain classrooms within the College of Liberal Arts and Sciences to have the posters while others do not. None of the remaining four academic colleges have any posters placed in their classrooms. What is the independent variable in this study? A) academic college B) classroom wall hangings C) gender of the student D) grade point average