They paid the fees before examination in interrogative​

In the interrogative form, the sentence becomes:

Did they pay the fees before examination?

Explanation:

The original sentence is in the affirmative form. The verb "paid" is in the simple past tense. To transform this sentence into negative, we must use an auxiliary that shows the sentence is in the past: "did". We place the auxiliary before the subject "they":

They paid the fees before examination. --> Did they pay the fees before examination?

Note that the main verb does not remain in the past. It goes back to its base form "pay" since the auxiliary already indicates the past tense.

the speech this question is referring to is president kennedy's special message to the congress on urgent national needs, may 25, 1961

kennedy responds in a very direct and concrete way to those thinking that communism is a positive system:

"yet their aggression is more often concealed than open. they have fired no missiles; and their troops are seldom seen. they send arms, agitators, aid, technicians and propaganda to every troubled area. but where fighting is required, it is usually done by others--by guerrillas striking at night, by assassins striking alone--assassins who have taken the lives of four thousand civil officers in the last twelve months in vietnam alone--by subversives and saboteurs and insurrectionists, who in some cases control whole areas inside of independent nations." (kennedy)

president kennedy presents communism as cowardly, as a hidden and treacherous weapon that strikes from the shadows like thieves, he represents the system as not even being capable of showing and open and overt attack or confrontation. to finish up the response, he expresses that the system attacks even a country's idependence and freedom.

"a" because he is appealing to logic as oppose to appealing to the audience's emotions.