What's beneath us? -- What do you know about soil? -- Land or water? -- Where is most of the fresh water? -- Groundwater -- How many oceans and seas? -- Why is the ocean salty? -- Water cycle diagram -- Where did the water in the puddle go? -- Weather predictors -- In which direction will the water swirl? -- Does the ocean influence our weather or climate? -- Coldest winter ever! -- Are they talking about climate or weather? -- What are the signs of global warming? -- How old is the earth? -- Is it a fossil? -- Sedimentary rock layers -- Is it erosion? -- Can a plant break rocks? -- Grand Canyon -- Mountains and beaches -- How do rivers form? -- What is the inside of the earth like? -- Describing earth's plates -- Where do you find earth's plates? -- What do you know about volcanoes and earthquakes? -- Renewable or nonrenewable? -- Acid rain -- What is a watershed? -- Is natural better? -- The greenhouse effect.