It's very common in early pregnancy for any symptoms to fluctuate from one day to the next. One day you might feel completely exhausted, only to feel fresh and re-energised the following day.
(Hope this helps!)
Answer:
Questionnaires
Explanation:
They allow both government and outside researchers to obtain estimates of a variety of health related topic or issue among either the entire nation or specific demographic group of the population.
And the survey design is cross section.
I think it’s ventricle and artery, but i’m not 100% sure! i
hope this helps anyway!
B : taking oxygen into the body
