What do microbiologist do ?

They study Microoganisms

Explanation:

They study micro (meaning small) organisms, for example, bacteria and algae, which is extremely minature. It is difficult and dangerous if left infected, but their work is sucessful if worked with the right tools, they try to understand how microorganisms live in their small environment

"d.) carbon dioxide and hydrogen sulfide"

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

i hope this : )