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**Independent Variable (IV):** The independent variable in this experiment is the concentration of the salt solution that each sunflower plant receives. It's the factor that the researcher intentionally varies to observe its effect on the plants.

**Dependent Variable (DV):** The dependent variable is the height of the sunflower plants after 2 weeks. It's the outcome or response that is measured to determine the effect of the different salt concentrations.

**Controlled Variables (CV):** Controlled variables, also known as constants, are the factors that the researcher keeps constant and unchanged throughout the experiment to ensure that any observed differences in plant height are due to the variation in salt concentration. In this experiment, some controlled variables might include:

- The type and species of sunflower plants used.

- The amount of sunlight each plant receives.

- The volume of saltwater solution applied to each plant.

- The soil type and quality.

- The temperature and humidity of the environment.

- The duration of time the plants are watered with saltwater (2 weeks, in this case).

By controlling these variables, the researcher can isolate the effect of salt concentration on plant height and draw conclusions about how different concentrations of saltwater impact sunflower growth.