xavier drew a diagram to compare the roles of oxygen and hydrogen in photosynthesis.

which label belongs in the area marked x?

enters plant as a part of water
combines with carbon dioxide
is released into air through stomata
is stored in leaves for later use

a

explanation:

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.

which