How do oceanographers define salinity

Which mantle is under the crust the upper mantle or the lower mantle i think it's upper let me know if i'm right

Ayoung boy has been found and police are trying to locate his family they take a dna sample from him and begin collec dna samples from families who have missing children if police use dna samples only from the fathers, which type of dn technology can they use to identify the boy's parent? y-chromosome analysis omtdna (mitochondrial dna) analysis vntrs (variable tandem repeats) o pcr (polymerase chain reaction) analysis

What happens during the experiment stage of the scientific method