Question

which best describes the present - day universe?
opaque, expanding very slowly, stars produce heavy elements
transparent, expanding at an accelerated rate, stars produce heavy elements
opaque, expanding at an accelerated rate, stars produce heavy elements
transparent, expanding very slowly, stars produce only hydrogen and helium

Explanation:

The present - day universe is transparent as light can travel through it over vast distances. Observations show that the universe is expanding at an accelerated rate, driven by dark energy. Stars through processes like nuclear fusion in their cores produce heavy elements (elements heavier than hydrogen and helium).

Answer:

transparent, expanding at an accelerated rate, stars produce heavy elements