water has a density of 1g/mL. there are four rocks that all have he sam volume of 10 cubic centimeters. the mass for each of these rocks are 30 grams., 20grams, 12grams, and 8 grams whith of the four rocks will float when placed in water

the population of unionid mussels in the hudson river decreased after zebra mussels were introduced. zebra mussels, a nonnative species, competed with the unionid mussels for food. the zebra mussels were able to outcompete the unionid mussels, allowing the zebra mussel population to increase dramatically over six years. the unionid mussel population decreased due to a lack of food.

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to improve her experimental investigation, dalila should add a row in which no fertilizer is used. by a having a contrasting row in which no fertilizer is used, she will have a control group that will her understand the effects of the fertilizer in the plant developments vs the development of the plant when no fertilizer is used.