Although most people know that exercise is good for the body, few realize the extent to which it is valuable to the mind. The blood circulates more rapidly after physical exertion, thus allowing all of the body’s organs to operate more efficiently. This increased activity enables the brain to receive more oxygen, thereby creating a higher capacity for concentration.
The main point in the argument above is that
(A) the greater the amount of oxygen the brain receives, the better the brain functions.
...
The main point in the argument above is that
(A) the greater the amount of oxygen the brain receives, the better the brain functions.
...
