Answer
See the image below.
Work Step by Step
First, we have to consider the parent function and then apply the transformations.
In the case of this function: $y=2-\sqrt x$, the parent function will be $y=\sqrt x$ (Black dotted line on the image)
Then we have to graph $y=-\sqrt x$, which is a reflection about the $x$-axis of the previous function (Red line graph on the image)
And finally, $y=2-\sqrt x$ (=> $y=-\sqrt x+2$), which shifts the graph upwards by 2 units (Blue line graph on the image)