Answer:
see below :)
Explanation:
Infectious are more easily spread nowadays becuse of an increased population. The more the population increases, the bigger the advantage an infectious disease has. As of right now, because everyone is wearing masks, their immune systems are being weakened. Another reason for this is because of the increase in chemicals in our foods, which are now being transferred to our bodies. All of the medications people are taking also have an affect on the spread of disease; it gives diseases a chance to mutate.
A type of learning in which a stimulus acquires the capacity to evoke a response that was originally evoked by another stimulus is known as classical conditioning.
In classical conditioning, a stimulus gains the ability to elicit a response that was first elicited by another stimulus. Almost by accident, Pavlov made this type of learning discovery while studying the canine digestive system.
He had surgically inserted a tube into a dog's salivary gland, which was used to collect the saliva the dog made after being given food powder to chew on. Before they were given food, several of Pavlov's dogs started to salivate.
To learn more about stimulus click here
brainly.com/question/20573834
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A scientist would use, C. Weather Balloon.
