Answer:
At the point when non-renewable energy sources are singed, they discharge carbon dioxide and other ozone depleting substances, which thusly trap heat in our air, making them the essential supporters of an Earth-wide temperature boost and environmental change. At the point when we consume oil, coal, and gas, we don't simply meet our vitality needs—we drive the current an unnatural weather change emergency also. Non-renewable energy sources produce huge amounts of carbon dioxide when consumed. Carbon discharges trap heat in the air and lead to environmental change.
Https://docs.microsoft.com/en-us/sql/relational-databases/tables/create-foreign-key-relationships
Answer:
Correct answer is option B (The reason for using supertypes is to minimize the number of nulls and to minimize the likelihood of redundant relationships)
Explanation:
Entity supertype
A entity supertype is a generic entity type which is related with one or more subtypes.
Use of entity supertype:
The reason for using entity supertype is to reduce redundant relationships and it is also used to minimize the number of nulls.
