During which period did manual fist appear a. pleistocene b. carboniferous c. cretaceous d. jurassic

Vaccines are weakened forms of disease causing microorganisms, which are given to patients to prevent disease. after the vaccine is administered, the immune system responds by creating a(n) to recognize the a.) antibody, antibiotic b.) antigen, antibody c.)antibiotic, antibody d.)antibody, antigen

Which worm has eyespots that are used to detect light? a fluke b marine worm c planarian d tapeworm

What is an example of a scientific question that galileo could not have answered with out this new tool?