Question

1. what are some of the reasons proposed for mass extinctions?

Explanation:

Mass extinctions can be caused by various factors. These include large - scale volcanic eruptions that release massive amounts of greenhouse gases and ash, altering the climate. Asteroid or comet impacts can also cause mass extinctions by creating huge dust clouds that block sunlight, disrupting the food chain. Climate change, whether natural or human - induced, can lead to habitat loss and species unable to adapt. Ocean acidification, often due to increased carbon dioxide in the atmosphere, can harm marine life and contribute to extinctions.

Answer:

Large - scale volcanic eruptions, asteroid or comet impacts, climate change, ocean acidification.