Answer:
the four main spheres of the earth are geosphere, hydrosphere, atmosphere and biosphere
Explanation:
geosphere consists of all rocks on Earth
atmosphere which are the gases that surrounds the earth
hydrosphere which is all the water on the earth
biosphere which are the living things on the earth
D. It gives the same results when experiments are repeated
Ivan Pavlov is most known for demonstrating conditioned lreflex in dogs.
<h3>what is conditioned reflex?</h3>
Conditioned reflex is a reflex action which has been conditioned to occur even without the stimulus which produces the reflex.
Ivan Pavlov is known to demonstrate conditioned reflex in dogs.
In his experiment, he trained dogs to salivate at the sound of a bell even if food which is the stimulus that produces salvation was not present.
Learn more about conditioned reflex at: brainly.com/question/24968947
