D.
Classical conditioning consists of a learned behavior over time. In this question the bell is stimulating the dogs wanting for food which cues the brain to salivate. Over time, the dog will correlate the bell being rung with food to being time to eat and will start to drool over it whether or not the food is present.
Answer:
A, B, E
Explanation:
The magma rising through the cracks makes new younger rocks close to the crack as the magma follows out and hardens. This means that rocks farther away from the crack are older because they where formed when they where right next to the crack. They are father away meaning they got pushed back as time went on.
Mid ocean ridges are a result of the spreading not the cause.
Because they are in the middle of the ocean and they are moving constantly i dought the mid ocean ridges are creating continents.
Answer: Your answer would be 9 million.
Explanation: The population is expected to raise 2 billion in 30 years. The population will go from 7.7 billion to 9.7 billion by 2050 which is closer to the answer choice D. Hope this helps :)