Professor Edwards is known for his difficult pop quizzes. Immediately before he announces a pop quiz to his students, he walks to the classroom door and closes it. His students soon learn to anticipate a pop quiz whenever Professor Edwards closes the classroom door. In the context of classical conditioning, closing the door has become a(n) .

In the context of classical conditioning, closing the door has become a(n) conditioned stimulus.

Explanation:

A conditioned stimulus, in classical conditioning, can be defined as a previously neutral stimulus that has become associated with an unconditioned stimulus, beginning to trigger a response.

It is very likely that closing a door didn't mean much to students in general (neutral). However, it was paired with the announcement of a quiz. Announcing a quiz (unconditioned) triggers a response - students feel surprised, anxious, worried, etc. After pairing up both stimuli a few times, students learn to associate them. Now, closing the door is a conditioned stimulus. Even if the professor does not announce a quiz, students will feel anxious and worried just by watching him close the door.

the first settlements began along the huang river because of the importance of the huang river in the beginning of china. it goes back to the story, “the tale of emperor yu”, which references the tale of the great flood, which was caused by the huang river and was believed to create and influence china’s making.

which sentences ? that question is incomplete