It enters the heart via the pulmonary veins
Answer:
Cross Sectional , Stratified Study
Explanation:
Research needed to gather primary data to compare attitudes towards energy brand between different ethnic groups : is Cross Sectional, Stratified Study .
Cross Sectional research is about studying various sample units at a particular point of time. Eg : Studying various ethnic groups at a point of time.
Stratified Study is based on sample drawn from various strata i.e sub population groups. It is a better representative sampling form, as encompasses all component groups of sample. Eg : Studying various subgroups (ethic groups) at a point of time.
Yes it is. Because it is always unsafe to use things like that, that are not secure.
