Choose the statement that is true. (A) Robert Hooke was the only scientist to make his own microscope
(B) Robert hooks creation of the microscope was the first time that scientists use lenses
(C) Scientists needed to develop new technology to be able to see and identify cells
(D) Scientists knew that sells existed before the microscope; they just hadn't seen one

i think the answer is c

parasites can detrimentally affect their host, but also must not allow their host to die before they can complete their life cycle. some parasites have complex life cycles with many different hosts, and have had to find ways of persisting in many different environments during the change from one host to another. ectoparasites live outside the body of the host, and can more easily  disperse, but are  more exposed to predators, parasites, parasitoids. endoparasites live inside the body of the host, and are therefore protected from the outside environment. but they can be  attacked by the host's immune system. they have therefore developed  mechanisms for dispersal such as  complex life cycles.