What is a planetary nebula?
A. gas created from the remains of planets that once orbited a dead star
B. interstellar gas from which planets are likely to form in the not-too-distant future
C. the remains of a high-mass star that has exploded
D. gas ejected from a low-mass star in the final stage of its life
Answer:D
What is a planetary nebula?
A. gas created from the remains of planets that once orbited a dead star B. interstellar gas from which planets are likely to form in the not-too-distant future C. the remains of a high-mass star that has exploded D. gas ejected from a low-mass star in the final stage of its life