C because the heart pumps normally with a constant pressure but when it is lower it needs to push harder to get the blood to where it needs to go causing it to malfunction
Therefore, it takes 40 sec to perform the work.
Are you referring to vocal cords?
No, the continents are much younger because new crust forms there. No, the ocean floor is much younger because new crust forms there. Yes, both the ocean floor and continents are constantly forming new crust. Yes, both the ocean floor and continents were formed at the <em>same time</em>.
