Question

A student is creating a pamphlet for a science project to raise awareness on global warming. The student wants to revise the introductory paragraph to improve the subtopic – the purpose of greenhouse gases. Read the following excerpt from the student's draft and complete the task that follows it.

Over the past century, the earth’s temperature has risen approximately 1.4°F. This change may sound insignificant; however, these small changes can result in major, and potentially dangerous, shifts in the earth’s climate and weather patterns. These small changes in temperature are largely the result of increasing concentrations of greenhouse gases in the atmosphere. Not all atmospheric gases are greenhouse gases. Greenhouse gases support human life. However, human activities have greatly increased the amount of greenhouse gases, particularly carbon dioxide, in the atmosphere.


Revise the underlined sentence to improve the introduction of the subtopic – the purpose of greenhouse gases. Choose the best sentence from the choices below.
A.
Atmospheric gases become greenhouse gases when they serve to trap heat inside the earth.

B.
Climate change produced by greenhouse gases is largely the result of a lack of concern for the environment.

C.
Greenhouse gas emissions can be produced from several activities, including electricity production, vehicle and equipment emissions, burning fossil fuels for energy production, and deforestation.

D.
Because they are vital to life on earth, greenhouse gases should be regulated by strict laws.

Answer 1

A

Choice A best explains the purpose of greenhouse gases by describing their heat-trapping role. The other options are off-topic or opinion-based rather than defining what greenhouse gases do.