Answer:
I believe the answer is B
It is tested with the blood gas test
Only toms idea could be scientific since it is testable, can be tested by others, have a hypothesis, and be proven
The effects of exercise on the circulatory system. This provides the muscles with the necessary oxygen and nutrients to provide the muscles with energy. During exercise strokevolume increases because: more blood is sent back to the heart due to the muscles squeezing blood in the veins. and I'll try to answer the other one just wait
Atmosphere))))))))))))(())(()))