<image> I am the clever little judge. (Tick "√" for correct, and "×" for incorrect)
1. If the radius of the base of a cylinder is doubled, the volume of the cylinder will be quadrupled.
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2. The volume of a cone is equal to that of a cube with the same base and height.
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3. If the lateral surfaces of two cylinders are equal, their volumes must be equal.
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4. A 10:1 scale means 10 centimeters on the map represent 1 centimeter in reality.
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5. If A is inversely proportional to B, and B is inversely proportional to C, then A is directly proportional to C.
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6. Negative numbers are all smaller than 0.
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