Which statement is true?

kennedy’s delivery was as important to the success of his speech as the words he chose to say.

kennedy’s speech was short because he wrote his speech only a couple days before the inauguration.

at the time of kennedy’s election, america was a peaceful and prosperous country.

john f. kennedy’s speech was criticized for having random references and scholarly words that most of his audience could not understand.

Among all of the given options, only "Kennedy’s delivery was as important to the success of his speech as the words he chose to say." is correct. All other options are either wrong or they just lack some missing information. For his inaugural speech, Kennedy applied a better use of rhetoric and it was addressed to the popular audience. Therefore, working through the answers we find that only the first option is correct.

because each is self-sufficient.  

technical documents should be clear and precise. basically, clarity is the key element in a successful technical document.