Answer:
answer is B
Explanation:
The table below shows the wavelengths for some electromagnetic waves
Answer:
bass limestone
Explanation:
if I'm right bass limestone is the fourth one because 3 are under it
Another name for these two words is "constant" and you want to have a "constant", because you want something to compare your experimental group to, to see whether data had changed or not. So you have placebos or a double- blind to compare your experimental group to it and also so you know you don't have a bias or anything in the study.
