True. Biking or walking exercises the leg muscles more than riding in a car would.
The best answer for the blood vessels' valves would be these are veins that would then help in preventing the back flow of blood because the walls have small muscle to pump the blood back to the heart.Hope this is the answer.
Answer:
The correct answer is - option D.
Explanation:
The study conducted by the Mosher and his associates 2005 found about the sexual orientation and normal sexuality of an individual showed that the vast majority of participants had engaged only in heterosexual behavior.
Only 6.5% of total participants had exclusively engage in homosexual behavior. It shows that majority of individuals are involved sexually with opposite sex.
Thus, the correct answer is option D.