Question

(blank) are nasty email exchanges in which a few people fight, but cc a group of others.

Explanation:

Identify the key terms

Analyze the sentence clues: "nasty email exchanges", "people fight", and "cc a group of others".

Define the concept

Using the Digital Communication knowledge point
In online communication, hostile and insulting interactions are called "flames." When these exchanges escalate into a series of angry, public messages involving multiple participants or copied observers, they are known as "flame wars."

Determine the correct term

The plural form "Flame wars" fits the blank grammatically ("... are nasty email exchanges...").

Answer:

Flame wars are nasty email exchanges in which a few people fight, but cc a group of others.