Answer
$2^3
\\2^2
\\2^1
\\1$
Work Step by Step
The expanded form of $1101_{\text{two}}$ is:
$1101_{\text{two}} = (1 \times 2^3) + (1 \times 2^2) +(0 \times 2^1) + (1\times 1)$
Thus, the missing expressions in the given statement (in order) are:
$2^3
\\2^2
\\2^1
\\1$