the answer is c body composition
Answer:
1920s and 1930s,
Explanation:
it's worth reiterating that helmets were not mandatory. That wouldn't happen until 1943. During the 1920s and 1930s, variations of the leather helmet appeared, but in 1939, the game changed –or at least became safer– when John T. Riddel introduced the first plastic helmet
Answer:
Genetic mutations causing the malfunction or absence of one or more of the regulatory proteins at cell cycle checkpoints can result in the "molecular switch" being turned permanently on, permitting uncontrolled multiplication of the cell, leading to carcinogenesis, or tumor development.
Explanation:
