~Hello there! ^_^
Your question: What waterway is the most significant to the regions due to its vast resources..?
Your answer: Tigris River is the water way that is the most significant to the regions to its vast resources.
The answer is option C.
Hope this helps~
"The Italian coast" is the one location among the following choices given in the question where you would <span>expect to find the highest human population per square mile. The correct option among all the options that are given in the question is the first option or option "A". I hope the answer has helped you.</span>
Answer: D) None of the above
Explanation: The subschema differs from the schema in that one denotes the appearance of data in the Database Base Management System (DBMS) while the subschema which is also referred to as the external schema is that subset of the schema is visible or relevant to the user. Thus, It is the view of the database which is visible to an application program. Virtual tables in a database usually represents an object structures like a table which is the result of running certain database commands or functions such as the create table, view, select and so on. Virtual tables are not stored directly in database files.