In 1775 Jenner began to study the relationship between cowpox (a comparatively harmless disease) and the more dangerous and disfiguring smallpox. ... He hypothesized that exposure to cowpox rendered the body immune from smallpox. After nearly twenty years of experiments, he developed the first vaccine.
Answer:
cockroaches are adaptive creatures that evolve according to their environment but never camouflage.
The two definitions are not animate or lifeless or the other definition is spiritless or sluggish.
Answer:
climate is weather and it affects ecosystem development
A renewable service can be renewed and used over and over again. so there for it is more valuable.