Can someone me this is so confusing

What are some possible short and long term medical concerns for crew members on longer space exploration trips

Which of the following is the best definition of aerobic respiration? o a. the cellular process that releases energy by breaking down glucose o b. physical activity that involves the repeated motion of large muscle groups o c. physical activity that increases heart rate and breathing rate o d. the cellular process that converts solar energy to chemical energy

9. the history of life on earth is recorded in