Answer:
Because flu viruses evolve so quickly, last year's vaccine may not protect you from this year's viruses. New flu vaccines are released every year to keep up with rapidly adapting flu viruses.
A force that creates something MUST be constructive force so the answer will be B.
Complex.
Hope this helps!
The answer is “Chromosomes are made of DNA!”
The answer is D cuz I just looked up a lot of it and saw the pics so ya its D
