Answer:
The correct answer is:
Includes at least two groups, one of which does not receive the experimental treatment. (B)
Explanation:
A controlled experiment is made up of at least two groups of participants (subjects). One group (the test group) receives the experimental treatment, which can be an intervention or a new drug to be tested etc, and the effect of the treatment on the subjects is measured, while the second group of similar subjects also known as the control group acts as a baseline and do not receive the treatment or intervention. They act as a baseline to ensure that the change observed in the treatment group was brought about as a result of the treatment.
<em>Note that repeating the experiment several times does not ensure accuracy of the result, rather it ensures reliability of the results hence option D is not correct</em>
I think the third one is the answer
Answer:
I believe the answer is B
Explanation:
<span>The average human red blood cell is roughly 6 to 8 micrometers wide. The width of a pin is this problem is defined as 1000 micrometers. Assuming we use the smallest size of a blood cell, then we divide 1000 by 6, and we find that roughly 166.66 (or 166 if you are rounding down) red blood cells will fit.</span>
