Glands of the exocrine system release their hormones a. directly onto the hormones target cells
b. directly onto the skins epithelial cells
c. into the bloodstream
d. into attached ducts

answer:

sequence 1- deletion

                  2- duplication

                  3- insertion

                  4- substitute

                  5- inversion

i think that is new experiments yield untrustworthy data and should be carefully considered, because you don't know what will happen with the experiments.