1. Circulatory system = the parts of the body that are related to the movement of blood
2. Internal system = the organs inside the body and how they function together
3. Muscular System = the part of the body that is made up of the muscles
4. Skeletal system = The bones found in the body
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:
respiration
Explanation:
<h3>the process of gas in the body is called respiration</h3>
The main difference is that the active one is strong than the passive one
