| A | B |
|---|
| forty-niner | A person who went to California in 1849 to search for gold. |
| telegraph | A machine that used electricity to send messages over wires. |
| transcontinental railroad | A railroad that crosses an entire continent linking the East and West Coasts |
| labor | Work. |
| time zone | A region in which people use the same clock time. |
| fjord | A narrow inlet of the ocean between cliffs. |
| earthquake | A sudden shaking of the ground caused by the movement and cracking of rock deep inside Earth. |
| volcano | An opening in Earth's surface out of which hot gases, ash, and lava may pour. |
| lava | Hot, melted rock that comes from a volcano. |
| crater | An opening in Earth's surface created when a volcano erupts and begins to throw out lava. |
| ecosystem | The relationship between living things and their nonliving environment, and their working together as a unit. |
| oil slick | The film of oil that coats the water after an oil spill. |
| wetlands | Low-lying land where the water level is always near or above the surface of the and |
| responsibility | Something that a person should do. |
| crossroads | Any place that connects people, goods, and ideas. |
| monarch | A king or queen. |
| produce | Fresh fruits and vegetables. |
| Pacific Rim | A world region that includes the states and countries that border the Pacific Ocean. |
| Ring of Fire | A world region that has many volcanoes and frequent earthquakes. |
