Question

climate change, sometimes called global warming, is an overall shift in climate across the planet. climates do change naturally over long periods of time, but recently temperatures have been rising faster. since 1880, earth’s average yearly temperature has risen about 1.5°f. climate change is caused by an excess of greenhouse gases like carbon dioxide and methane. these gases absorb heat from the sun and hold it in the atmosphere. some greenhouse gases are necessary to make earth warm enough to live. recently, however, the natural balance has been disturbed by human activity like burning fossil fuels and cutting down forests. because warmer air has more energy than cooler air, our changing climate can lead to more extreme weather events like hurricanes, heat waves, and flash floods.
what is the purpose of the underlined sentence in the passage?
choose one option
a to prove that fossil fuels are responsible for climate change
b to explain why earth’s average yearly temperature is rising
c to clarify that greenhouse gases are not always bad
d to provide a quote from a climate - change expert

Explanation:

The underlined sentence "Some greenhouse gases are necessary to make Earth warm enough to live" shows that greenhouse gases have a positive role (making Earth habitable) along with their negative impact (causing climate change when in excess). This clarifies that greenhouse gases are not always bad. Option A is incorrect as the sentence is not about fossil fuels. Option B is wrong as it doesn't explain the temperature - rise reason (the reason is excess gases, not the necessity of some gases). Option D is incorrect as it's not a quote from an expert.

Answer:

C. To clarify that greenhouse gases are not always bad