To solve the problem, we need to understand the relationships between the different types of musical notes and rests.
In music, a quarter rest is equivalent to a quarter note in duration.
A half rest is equivalent to two quarter rests.
Thus, to find the equivalent of a half rest, you can think of it as:
A quarter rest + ____ = A half rest.
Since a half rest (which is 2 quarter rests) is formed by adding two quarter rests together (1 quarter rest + 1 quarter rest), then:
A quarter rest + A quarter rest = A half rest.
So the answer to fill in the blank is:
A quarter rest is shown.