[fw.02]to increase the validity and reliability of the results of experiments with groundwater, several people should
repeat the results many times
study only pure sources of groundwater
obtain information only from secondary sources
provide different results of the same experiment

answer: a

explanation:

this website is for anybody really not just for girls just saying, also while a lot of males are mean and you know there are the few who are kind and then there's the nice-guys but then theirs also guys like me who are shy we don't get out much because there are people like you who exist who would most likely punch a guy in the face so next time just think about things before you post them to a website where guys and girls can see your question.

yes it is   dangerous

explanation:

because that foot is discusting and could get you sick