9. a) List four things that form or begin during the first trimester of pregnancy. (1 point) Marking brainiest!

fertIlization, morning sickness, slight body changes, period stops

Explanation:

The baby’s heart, spinal cord, skin, and red blood cells all begin to form during the first trimester of pregnancy.

Explanation:

Hope this helps! Have a nice day :)

maritime tropical may be your answer.

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.