Here's a hypothesis for the duckweed experiment: "if duckweed is grown at pH 5, then it will grow at the same rate as when grown at pH 7, or normal pH, because it can tolerate mildly acidic environments." Which elements should be controlled variables for this experiment?

Check all that apply.

- environmental pH

- ✓ timing of experiment

- duckweed population

- ✓ environmental light

- ✓ amount of nutrients

- ✓ environmental temperature

the answers for whoever needs it :)

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