Global warming refers to the rise in average surface temperatures on Earth. An overwhelming scientific

consensus maintains that climate change is due primarily to the human use of fossil fuels, which_____ (1) carbon dioxide and other greenhouse gases into the air. The gases trap heat within the atmosphere, which can have a range of effects on ecosystems, (2)_______rising sea levels, severe weather events, and droughts that render landscapes more susceptible to wildfires.

While consensus among nearly all scientists, scientific organizations, and governments is (3)__________ climate change is happening and is caused by human activity, a small minority of voices questions the validity of such assertions and prefers to cast doubt on the preponderance of evidence. Climate change deniers often claim that recent changes (4)______ to human activity can be seen as part of the natural variations in Earth's climate and temperature, and that it is difficult or impossible to establish a direct connection between climate change and any single weather event, such as a hurricane. While the latter is generally true, decades of data and analysis support the reality of climate change and the human factor in this process. In any case, economists agree that acting to reduce fossil fuel emissions would be far less expensive than (5)_____ with the consequences of not doing so.

1. A.returns B. Repeats C. Releases D. Retakes

2. A. Including B making C consisting D. Containing

3. A. Which B. What C. This D. That

4. A. Attributed B. Contributed C. Believed

D. Talked

5. A. Facing B solving C. Treating D. Dealing