Take a look at the image 1. Armando thinks that it is the very steep hill that makes this river narrow and deep, but his classmate thinks it is the small size of the sand grains that the water flows through. What information can the model provide us that would be used as evidence that Armando's idea is correct?

2. One limitation of Armando’s model is that all the water enters the model from one source: the water tank. Explain why this is a limitation of the model.

Based on their location in the atmosphere, the layers are able to have their own special characteristics. for example, most weather occurs in the troposphere. what occurs in each of the other layers?

Read the article about the fraser river, one of the most important rivers in canada. what is the most important species of fish in this river? why are the numbers of these fish declining?

Study guide for unit 2 ~ lesson 3 ,4, & 5 test, thursday, january 24th lesson 3 vocabulary erosion - deposition - landform- weathering- short answers 1. how do volcanic islands form? 2.why is deposition likely to occur outside a river bend? 3. in what conditions does soil form fastest? 4. which 2 earth’s systems interact to form a coral island? 5. a beach growing in size is most likely the result of 6. which type of islands are formed when a chunk of land breaks off from a larger landmass? long answers explain how plants can grow in small cracks of rock that do not appear to contain soil. lesson 4 vocabulary pollution - toxic - short answers 1. most farmers pollute soil by purposefully adding 2. what is the benefit of contour plowing? . 3. using nuclear power to produce electricity can cause water pollution by 4. why do scientists predict humans will run out of fossil fuels someday? 5.farmer spray crops with fertilizer and weed killer to the crops grow. how might this affect the hydrosphere? list two different ways you use fossil fuels. 1- 2- what are two other energy sources scientists and engineers are researching? 1- 2- lesson 5 vocabulary decompose- recycling - short answers 1. which of earth’s systems do you interact with when you wash your hands? 2. which of earth’s systems is polluted by exhaust gases from buses pollute? 3. why is it important to dispose of electronic devices properly? 4. where do people interact with all four of earth’s systems?