According to the National Climatic Data Center, “the most recent glacial period occurred between about 120,000 and 11,500 years ago.” Glacial periods always begin with a climate shift that causes global temperatures to fall. When the last glacial period began, the cold temperatures allowed glaciers to form and grow. For over 100,000 years, snow and ice dominated many landscapes across the planet.
Choose the sentence in this excerpt that indicates the author used facts from a study in his research.
1. “the most recent glacial period occurred between about 120,000 and 11,500 years ago.”
2. “Glacial periods always begin with a climate shift that causes global temperatures to fall.”
3. “the cold temperatures allowed glaciers to form and grow.”
4. “For over 100,000 years, snow and ice dominated many landscapes across the planet.”
