Can anyone give me examples of control groups ?

In an experiment in which blood pressure medication is tested, one group is given the blood pressure medication while the control group is given a placebo pill.

In a test of anxiety treatment, one group attends individual therapy sessions and receives a new medication. The control group receives only an inert pill.

A treatment for drug addiction is being tested. A group of meth addicts are given the treatment while the control group is given the placebo.

Researchers are testing the effectiveness of a drug intended to reduce symptoms of Crohn's disease. Many sufferers of Crohn's disease are recruited for the effort and the group that receives the placebo is the control group.

A treatment for hair loss in men is being tested. Men of the same age range are gathered. One group receives an application with the active ingredient while the control group receives an application that appears the same but does not have the active ingredient in it.

hope this helped you

"hydrogen bonding is the attraction of h atoms in the water molecule (slight + charge) to o atoms in a neighboring water molecule (slight - charge); it is a weak interatomic force. but it is still strong enough to the water molecules "stick" together."

i'm assuming that the correct answer is indeed the first one/ "a"..