Problem:OPTIONS:
- Australia
- Europe
- Africa
- antarctica

Answer the following question given this paragraph: Amphibians can be found in freshwater and moist terrestrial habitats throughout the world. The only continent without amphibians is Antarctica. Amphibians are especially numerous in temperate lakes and ponds and in tropical rainforests. Q: What is the only continent without amphibians? A:
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A: antarctica

Problem:OPTIONS:
- pH scale
- reactor
- litmus test
- an acid-base indicator

Answer the following question given this paragraph: An acid-base indicator is a substance that displays different colors when in the presence of an acid or a base. How does that work? An indicator is a weak acid that ionizes within a known pH range, usually about 2 pH units. We can represent the protonated form of the indicator molecule as HIn and the deprotonated form as In . The following equilibrium exists for the indicator. Q: A substance that displays different colors when in the presence of an acid or a base is called what? A:
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A: an acid-base indicator

Problem:OPTIONS:
- crater
- cavern
- valley
- caldera

Answer the following question given this paragraph: During a massive eruption all of the material may be ejected from a magma changer. Without support, the mountain above the empty chamber may collapse. This produces a huge caldera . Calderas are generally round, bowl-shaped formations like the picture in Figure below . Q: After a massive eruption what will a mountain collapsing above an empty chamber create? A:
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A: caldera

Problem:OPTIONS:
- signaling proteins
- harnessing molecules
- signaling neurons
- signaling molecules

Answer the following question given this paragraph: Q: Cells in a biofilm secrete what to recruit nearby cells? A:
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A:
signaling molecules