Problem:OPTIONS:
- hydrogen
- sugar
- quartz
- salts

Answer the following question given this paragraph: Dissolved mineral salts wash into the ocean. As ocean water evaporates, it leaves the salts behind. This makes the water saltier. Ocean water is about 3.5 percent salts. The main salt is sodium chloride. Q: Concentration of what, the substance left behind when ocean water evaporates, is about 3.5 percent? A:
****
A: salts

Problem:OPTIONS:
- systems
- additions
- Changes
- adaptations

Answer the following question given this paragraph: Some of the characteristics an organism has may help it survive. These characteristics are called adaptations . Some adaptations are better than others. Q: What characteristics of an organism help it survive? A:
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A: adaptations

Problem:OPTIONS:
- power insulators
- motion reducers
- cooling insulators
- electric insulators

Answer the following question given this paragraph: Materials that have high resistance to electric current are called electric insulators . Wood, rubber, and plastic are examples of electric insulators. Dry air is also an electric insulator. Q: What are materials that have high resistance to electric current called? A:
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A: electric insulators

Problem:OPTIONS:
- Tibet
- rain forests
- taiga
- ocean floor

Answer the following question given this paragraph: Scientists have learned a lot about the ocean floor. For example, they know that Earth's tallest mountains and deepest canyons are on the ocean floor. The major features on the ocean floor are described below. They are also shown in Figure below . Q: Surprisingly, where would you find the earth's tallest mountains and deepest canyons? A:
****
A:
ocean floor