What purpose do colons serve in a sentence or phrase?

Although william carlos williams rejected traditional verse forms he still believed that is was important to use poetic devices to distinguish verse from prose.

Johnny just received a failing grade on his science exam. lucy oversaw johnny’s paper, and she asked him about it. johnny snapped at her shouting, “it’s none of your business! ” which of the following is the psychological response johnny exhibited towards lucy? select one: a. dismay b. irritability c. hesitation d. hopelessness

Fill in the blank: modernism can be seen in movies with (choose the best answer a. a technological and scientific view b. a fantasy type twist c. an anti-consumerism slant d. a realistic and non-imaginative slant