When using the scientific method, what should be the first step?

Observation

Explanation:

The scientific method is a series of steps or procedure through which scientists come to conclusion about the natural world.

Chronologically, the scientific method involves the following steps:

Hence, the first step is observation.

lipid

explanation:

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.

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