I’ll help you with 20. Freezing happens when the molecules of a liquid get so cold that they slow down enough to hook onto each other, forming a solid crystal. For pure water, this happens at 32 degrees Fahrenheit, and unlike most other solids, ice expands and is actually less dense than water
"Recombination" and "Genetic drift" are the two main sources among the following choices given in the question that lead to increased genetic variation. The correct options among all the options that are given in the question are the third and the fourth options. I hope the answer has helped you.
2 kidneys
2 ureters
bladder
urethra
Answer:
The ventricles are not reaching systole in every cardiac cycle.
Explanation: