A conjunction, noun, or verb
Huhhhh what are you talking about
A.
The conflict was unavoidable and expected to be painful.
C.
All of the points should be coherent with the main idea.
After they rested a few days, the aliens revived sufficiently to explore.
.
In order to check comma placement, swith the sentence around and see if it still makes sense. In this case it would be:
.
The aliens revives sufficiently to explore after they rested a few days.
The URL does NOT need to be in a not card