Final answer:
An ineffective preventive measure for acid deposition is adding lime to neutralize acidified lakes. This does not prevent acid deposition but instead treats the resulting effects. Effective measures target reducing emissions of SO₂ and NOx at their sources.
Step-by-step explanation:
The action that would be an ineffective preventive measure for acid deposition is 'Adding lime to neutralize acidified lakes.' While this action can help to mitigate the effects of acidification by neutralizing the pH of the water bodies affected, it does not prevent acid deposition itself. Effective preventive measures target limiting the emissions of sulfurous and nitrous compounds at their sources. These measures include reducing coal use, burning low-sulfur coal, switching to natural gas or renewable energy resources, and removing SO₂ and NOx from motor vehicle exhausts.
By employing technologies such as coal scrubbers which react SO₂ with lime to form calcium sulfite, and shifting towards low sulfur coal, industries contribute to a significant reduction in the emissions that lead to acid rain. These controls at the source are vital in preventing acid deposition before harmful effects on the environment and man-made structures can take place.