During periods of vigorous physical activity, a person's breathing and heart rates increase. this enables the cells of the body to perform more efficiently because it the cells to

Remove the metabolic waste quickly

Explanation:

The increased breathing rate ensures intake of oxygen into the body while the increased heart rate leads to increased oxygen supply to the muscles. The oxygen serves to remove the metabolic waste (for example: carbon dioxide) produced during muscle contraction and thereby, enables the cells of the body to perform more efficiently.

"menstrual cycle is a complex cycle that consists of several processes. order of occurrence of steps in menstrual cycle are as follows:

1. high progesterone levels maintain the endometrium lining of the uterus.

2. endometrium lining breaks down and low levels of estrogen stimulate the pituitary to release fsh and lh.

3. fsh and lh stimulates the follicles to develop and the oocyte to produce estrogen.

4. rising estrogen levels suppress fsh production and development of other follicles.

5. a spike in lh causes follicle to rupture.

6. a breakdown of corpus luteum causes progesterone level to drop."

what's the question ?