| A | B |
|---|
| Ice Age | A period of time that began more than 70,000 years ago when thick sheets of ice covered most of the earth |
| glacier | A thick sheet of ice |
| culture | Way of life of a group of people, including their beliefs, crafts, religion, and customs |
| strait | A narrow waterway that connects two larger bodies of water |
| land bridge | An area of land connecting two large land masses |
| surplus | An amount greater than what is needed |
| specialize | To spend most of one's time doing one kind of job |
| religion | A belief in God or gods |
| civilization | A culture that has developed systems of government, religion and learning |
| empire | Lands or people ruled by one group or leader |
| irrigation | Bringing water from dry fields or lakes by means of ditches |
| history | The study or record of what has happened in the past |
| historian | Try to find out what happened long ago |
| primary source | Something that comes from the time being studied |
| secondary source | An account of the past written by someone who was not an eyewitness to the events |
| archaeologists | Scientists who looks for and studies artifacts |
| artifact | An object such as a tool, weapon, or clay pot, that was left behind by people long ago |
