Organized systems of agriculture, the maintenance of herds of domesticated animals, and permanent, year-round settlements marked the. a. Paleolithic Era c. Bronze Age b. Stone Age d. Neolithic Era Please select the best answer from the choices provided A B C D

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.

during expiration the diaphragm relaxes, which causes the diaphragm to move downwards. the contraction of diaphragm increases the space for expansion of lungs. hence, the diaphragm relaxes and positioned downward during expiration.