A student was preparing to perform a flute solo in an auditorium for the spring band concert. The teacher went to the back of the auditorium and discovered that the sound of the flute was going to need to be amplified for people in the back to hear the solo. The amplified sound produced a wave or b wave .

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 only hydrogen and helium transparent, expanding very slowly, stars produce only hydrogen and helium