Me with this 60 points,5-star rating, an and marked as branliest.

robert was told by a friend that if you place unused batteries in a refrigerator, they would last longer. he wanted to see is this was true. he hypothesized that if the temperature is colder, then the battery power would last longer. robert brought some batteries. he placed 1 of them in the refrigerator,1 on his desk, and 1 on a heating pod. one week later, robert tested 3 batteries with a battery tester. he repeated the test 3 more times for a total of 4 weeks. he used the same size batteries.

independed variable:

dependent variable:

constants:

control:

The independent variable here is the temperature of the batteries. It is the variable being manipulated throughout the experiment.

The dependent variable is the amount of battery power each individual battery will have after testing.

The constants are the different temperatures each of the three batteries are exposed to, as they don't actually change at any point during the experiment.

And finally the control group is the battery not exposed to a modified temperature, i.e the one sitting on the desk.

Hope this helps!

answer: "circumcision is a common procedure in which the skin covering the tip of the penis is surgically removed."

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link: