2.+Many+of+the+phenomena+that+we+observe+on+Earth+involve+interactions+among+components+of+air,+water,+and+land.

MAJOR UNDERSTANDINGS

2.1a Weather is the condition of the outside air at a particular moment. 2.1b Weather can be described and measured by

2.1c Water is recycled by natural processes on Earth. 2.1d Erosion and deposition result from the interaction among air, water, and land.

2.1e Extreme natural events (floods, fires, earthquakes,volcanic eruptions, hurricanes, tornadoes, and other severe storms) may have positive or negative impacts on living things.