Nuclear fusion can be and it technologically feasible for commercial power production.
a. on the sun; is not
b. in nuclear power plants; is
c. in stars; is
d. underground; is

fire could start, buildings collapsing, and ash falling from the sky.

explanation:

this is because the buildings or plants could catch on fire and the buildings would most likely collapse. lastly ash would fall because all the burning would cause ash to fall from the sky.

hope this .

let that person have a turn to speak : )