Individuals may or may not have control over __________, elements ...

[beccaep]

Individuals may or may not have control over __________, elements in their surroundings such as pollution and temperature.
 Fill in the blank(s) with correct word

Question 2

When an elite athlete decides to donate blood during training and then have it transfused back into his body just before a competition, he is trying to increase his _____ and therefore the amount of _____ available to tissues in order to increase the rate of _____ energy metabolism.
 a. myoglobin, cytochromes, aerobic
  b. transferrin, glucose, anaerobic
  c. hemoglobin, oxygen, aerobic
  d. hemosiderin, ATP, anaerobic

[duke02]

Answer to Question 1

environmental factors

Answer to Question 2

c

[beccaep]

Excellent

[tandmlomax84]

Gracias!