To express that the event will continue until a specific time in the future the sentence would be rewritten in future perfect progressive tense. Future perfect progressive tense refers to the state of action that will be continuing until a specific time in a future.
Future perfect progressive tense is formed as subject + will+ been + present participle of the verb.
Therefore, the sentence would be rewritten as,
The students will have been painting for an hour without a break to create their Rockwell-inspired art.
<span>Which of these best describes the mood of these lines?
(a.) hopeful</span>
The words that best describe how the author ironically portrays Mr. Symmes in this line are, "heathenish" and acting in a sort of "Christianized" manner. The word heathen describes a person who does not belong in any religious group. In short, he is called a pagan. But in this line, it was mentioned that Mr. Symmes was acting like a Christian, which makes this line ironic.