Why is history fun?
Who wants to talk?
Why is science so fun?

History is fun because it’s something that  you love reading or watching

Explanation:

1) Why is history fun?

History is so interesting because learning about famous and everyday people, events, stories, and the successes and failures of people, nations, civilizations, and organizations can be important and meaningful.

2) Who wants to talk?

sorry I just don't have time to talk.

3)Why is science so fun?

Because it contains literally everything in this world as a field of study. Science is all about finding answers and using those answers. It's fun to understand why things behave the way they do. It's fun to think about quantum particals and their weird behavior.

yes that is correct and good

explanation:

i'm not sure i completely understand your question, but i will do my best.

i think the answer you are looking for is sequence. (see below)

a repeated melodic fragment would be best defined as repetition, while repeated chords (different or the same) could be a chord progression. however, you then mentioned the chord and melodic fragment beginning on higher or lower pitches, in that case, the answer could be best defined as a sequence. the definition of a sequence is as follows: "the restatement of a motif or longer melodic (or harmonic) passage at a higher or lower pitch in the same voice."

let me know if this !