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How much of the air supports burning ? Is air a mixture ?
How can we explain burning ? - What is a flame?
How does a fire warm us? — Hot-air furnaces. Heating
posed ? What causes dew and frost? - How are clouds
the heavenly bodies rise and set? What is the path of a
body have weight? In what direction does the earth pull ?
What is the density of water? Why does a body float?
Why does a pendulum swing? — What is a force ?
What is a substance ? Can substances be changed ?
What is phosphorus like? What is a match? — Ex-
water boil? – How is ice made? How is ice cream frozen?
- How do bodies of water affect climate? How does
rocks? How are stratified rocks formed ?
weathering ? How is our soil formed ? What is the
preserve food ?
How is meat smoked ? - What are salting