Read the passage and choose the best option to fils each blank
The Earth’s average (1) _________has increased by about 2 degrees Fahrenheit during the 20th century. What’s the big deal?
Two degrees may sound like a small amount, but it’s an unusual event in our planet’s recent history. Earth’s climate record, (2) _________in tree rings, ice cores, and coral reefs, shows that the global average temperature is stable over long periods of time. (3) _________, small changes in temperature correspond to enormous changes in the environment.
Scientists have high confidence that global temperatures will continue to rise for decades to come, largely due to (4) _________gases produced by human activities. The Intergovernmental Panel on Climate Change (IPCC), (5) _________more than 1,300 scientists from the United States and other countries, forecasts a temperature rise of 2.5 to 10 degrees Fahrenheit over the next century.