An infected individual's respiratory tract best describes
the stage of the infection chain.

d) center of the mid-ocean ridge

give brainleysest

sinserly,

steckh986

some of your causes might be acidic rain or natural wildfires that cause the parks to be degraded

hope this any more questions i am here plz mark brainliest

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.