20 points! the cdc (centers for disease control) is a federal agency that monitors the spreading of various diseases and health issues. they have done extensive research on the effects of tobacco on a person's health. the cdc does a study on smoking with the hypothesis, "if a person smokes more cigarrettes, then they are more likely to develop heart disease". which of the following should be a controlled variable for this experiment? choose all that apply. 1. amount of smoking a person does 2. weight class of the person 3. state where the person lives 4. whether or not the person develops heart disease
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Chemistry, 23.06.2019 00:30, coralaguilar1702
What is calcium oxide+diphosphorus pentoxide--> calcium phosphate balanced
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Chemistry, 23.06.2019 02:00, raulflores01
Which best describes the present-day universe? opaque, expanding very slowly, stars produce heavy elements transparent, expanding at an accelerated rate, stars produce heavy elements opaque, expanding at an accelerated rate, stars produce only hydrogen and helium transparent, expanding very slowly, stars produce only hydrogen and helium
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20 points! the cdc (centers for disease control) is a federal agency that monitors the spreading of...
Mathematics, 28.05.2020 20:01
History, 28.05.2020 20:02
History, 28.05.2020 20:02