Internalize an externality, economics homework help

Short answers:1. What 2 kindsof government policy can internalize an externality? Give an example of"Positive Externalities" for private goods. Which policy do yourecommend in this case? Explain.2. What 2 kindsof government policy can internalize an externality? Give an example of"Negative Externalities" for private goods. Which policy do yourecommend in this case? Explain.3. Give anexample of "Public Goods". Explain how the non-exclusion andnon-rival nature of it results in the "Free Rider Problem" that leadsto a less-than-optimal supply of these goods from the private market.4. Give anexample of "Common Resources". Explain how the non-exculsion butrival nature of it results in overuse, so that there is a greater-than-optimaldemand for these resources from the private market.