Grandma Hippity Hop is worried about the ice that will be forming on her sidewalk this winter. She doesn't have money to waste on sidewalk salt that is ineffective, so Brenda decides to do some testing for her. Indepedent Variable -
Dependent Variable -
Controlled Variables: (There are at least 5. Please list 2)

Independent variable- SIDEWALK SALT

Dependent variable- ICE FORMATION

Controlled variables- same size of ice, same sidewalk

Explanation:

Based on the information given in this question, Brenda is helping Grandma Hippity Hop test the effect of sidewalk salt on the formation of ice on her sidewalk.

In an experiment, the independent variable is the variable that is changed or manipulated by the experimenter. In this case, the SIDEWALK SALT is the independent variable because it is the one being changed i.e used or not used.

Dependent variable is the variable that responds to the changes made to the independent variable. It is the variable that is measured or recorded in an experiment. In this case, the ICE is the dependent variable because its formation is dependent on the SALT (independent variable).

Controlled variable or constants are variables of an experiment that are kept unchanged throughout the experiment. In this case, the SAME SIDEWALK AND SIZE OF ICE are used, hence, they are the controlled variables.

the menstrual cycle – higher tier. negative feedback mechanisms affect the production of hormones in the menstrual cycle. oestrogen also stimulates the release of lh (luteinising hormone) from the pituitary gland, which in turn controls the production of progesterone.