The right option is; the protagonist and antagonist
The protagonist and antagonist are the forces that struggle in the plot of a story.
The protagonist and antagonist are significant characters that cause conflict in a story. The protagonist is the main character of a story usually referred to as the lead, while the antagonist is the character that actively opposes the protagonist’s goals and is usually referred to as the villian. Stories can have more than one protagonists and antagonists, and active characters can also change between these roles in the story.
The correct option is C.
The recovery process is used to remove refrigerant from an AC system in order to store it in an external container. The refrigerant has to be removed because it destroys ozone layer and cause global warming. It also has negative effects on the living organisms generally.<span />
Increased exchange surface provided by their membranes
PHS defines an investigator as an individual, regardless of tittle or position, who is responsible for the design, conduct or reporting of research funded by the PHS or proposed for such funding. This includes key personnel identified in the grant application, progress report or other report submitted to the funding agency by the Institution.
