As blood flows through the capillaries in the lungs, it drops off and picks up .

The correct answer is-

As blood flows through the capillaries in the lungs, it drops off and picks up carbon dioxide and oxygen respectively.

Deoxygenated blood ( carrying carbon dioxide) reach lungs from right ventricle of heart via pulmonary artery, which decreases diameter and forms capillaries on the alveoli ( tiny air sacs in the lungs for the gaseous exchange).

Thus, oxygen is taken up by the blood ( so as to transport it to the rest  of the body) whereas carbon dioxide ( which is a waste product of metabolism in the body) is dropped at lungs, which is then released out of body through exhalation.

"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."