Question

a supernova may leave behind a white dwarf, when the outer portion of a red giant expands and is blown away, a dropdown is left behind. the most - massive stars may become dropdown, which are no table. options: neutron star, black hole, white dwarf

Explanation:

1. For the first blank (after red giant's outer portion is blown away): A red giant (low - to - medium mass star) sheds its outer layers, leaving a white dwarf.
2. For the second blank (most - massive stars): The most massive stars, after supernova, can become black holes (neutron stars are also possible but black holes are for the most massive, and they are not stable in the sense of being a normal star; white dwarfs are for lower mass).

Answer:

First blank: white dwarf
Second blank: black hole