In the chemical reaction below, calcium metal and water react to form calcium hydroxide and hydrogen gas. calcium metal + water → calcium hydroxide + hydrogen gas

Calcium and water are the reactants in this chemical reaction, whereas calcium hydroxide and hydrogen gas are the products that are formed. Once the reaction reaches completion,
A.
the total mass of the products will be greater than the original mass of the reactants.
B.
the total mass of the products will be equal to the original mass of the reactants.
C.
the total mass of the products will be less than the original mass of the reactants.
D.
the products of the reaction will have changed back into the reactants.

"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."

"a.) well–developed vascular system."

air enters through the nose, moves through the nasal cavity, the pharynx, the larynx, enters the trachea, moves through the bronchi andbronchioles till the alveoli.