Assume as what happens in a pot of water as it get heats.. hot becomes less dense, rises and cools, becoming more dense then sinks- that's called CONVECTION
So D- is the right answer
A control group is sort of the normal group. The group you aren't changing or messing with. It is to show what the species/experiment acts like on its own in response to something without you having to change it at all.
With an experimental group, you are changing something about the subject before putting it in the conditions it will need to respond to.
I don't entirely understand, but I know the control group is constant, unchanging. It sort of helps with distinguishing things. I have examples of experiments if that will help you understand what a control group is to answer the question. I also have a The Death Cure example if you have seen or read the book. I hope you do not fail this assignment, but even if I did not answer with an answer you were looking for, it could have helped you answer the question on your own.
I saw somewhere a similar question, though I was given the answer choices. If this is the answer you are looking for: variable(s).
Control groups don't use variables because you aren't changing them.
They are two very different tunings. Urination is basically releasing your urine while the other one relates to releasing sperm..
The answer is: A nerve block
A nerve block is a procedure of regional anesthesia, surgical or medical injections of substances, aimed at removing pain for a period of time, up to the final eradication of this pain, for therapeutic or diagnostic purposes.This procedure involves the local injection of anesthetic instead of pain. The anesthetic is usually directed to the nerve that serves the pain area.
