Answer:
A population or community research line can be carried out, wherever at a certain point in time, regardless of whether it is a cross-sectional study.
In addition, the people who would be the population to be studied or the object of study might or might not know the cause of the study (blind) while the researcher could be experimentally participatory.
Explanation:
They are prevalence studies, in which the presence of a health condition or state is determined in a well-defined population and in a determined time frame: one day, one week, a particular moment in life, even if it does not temporarily coincide in all the subjects (for example, the blood pressure figures at the time of entering the school or at the beginning of the holidays, the prevalence of diabetes in hospitalized patients on a given day, etc.).
They are like "photographs" of a state of affairs at a given moment. The simultaneous determination of what is understood by exposure and event does not allow defining causality.
Answer:
atoms or molecules
Explanation:
Gas particles are constantly bumping into each other and the borders of their container.
Answer: helium(He)
Explanation: Helium has only 2 electrons in the outermost energy level, but all of the other elements in its column have eight.
I am pretty sure that the answer is B. extrusive rock. I hope that this helps you!! Good Luck!!