The italicized word OVER can be used either as a preposition or as an adverb in a sentence. In this particular sentence, the correct answer is adverb.
When over is used as an adverb, it is not followed by any word which would create a phrase along with it (as is the case here). Compare OVER as a preposition (A bird flew over the lake - we can see over what) and OVER as an adverb (Could you come over - we don't know over where or what).
Focus on looking back over your arguments frequently. Keep yourself on track for the point that you're trying to create by staying both true and relevant to the topic at hand. Also, provide good support for your argument. Avoid making assumptions. Lastly, compare your argument to the list of all fallacies. Does your piece fall under any of those at any time? If so, you then know what to fix. Hope this helps.
Answer:
We have had a lot of troubles in the past. World Wars, Flu epidemics. Countries have changed. Countries allied each other to defeat others. But the only time when all the countries come together to defeat the same enemy -- Corona virus.
When a protagonist has a strong belief against the majority of the community or surroundings and decides to act on it