Which of the following reduce the prices of higher-cost products, such as automobiles, for consumers in the 1920s. installment plans the introductions of coupons assembly lines the development of advertisements.

answer: in october 1962, an american u-2 spy plane secretly photographed nuclear missile sites being built by the soviet union on the island of cuba. president kennedy did not want the soviet union and cuba to know that he had discovered the missiles. he met in secret with his advisors for several days to discuss the problem.

explanation:

a. theta waves. this is because the person is in a light sleep which means the brain waves would show these kind of waves.