Answer:
b. foreign key
Explanation:
In the database world, a foreign key is a field on one table and a primary key for another table. The purpose of a foreign key is to provide linkages between two or more tables. Given two tables A and B, and making A the point of reference, a primary key is a field that is unique in A while a foreign key is unique in B.
On another hand, a composite primary key is a combination of two or more fields/columns on database table that can be used to uniquely identify each row in the table.
In the database lingua, what we have is a unique key not a distinct key, though the two words are similar in meaning.
A duplicate key is used when an information may be repeatedly entered on a table.
So the correct option is a foreign key.
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In many, many ways. Here's some things you can talk about:
•Previously we stored patient data by hand on paper. Now we use computers to store it. This is better because what if we accidentally lost/destroyed the papers or it burned down? With computers this risk is minimised.
•We can now diagnose patients with problems with much more precision thanks to advances like MRI scanning, CT scans, and X-rays. This means we can pinpoint problems rather than guess what’s wrong.
•Prescriptions for medicine can now be arranged online and delivered to your door in some areas, whereas previously you would have to walk in and get the medicine which could be time consuming.
•We now have phones to dial 911 for emergency ambulance services. This has revolutionised how quickly responders can respond to life threatening events.
There’s much more to talk about, but all of the points above are a sold start.
Mac os is based on the UNIX operating system.
The Rhineland was turned into a demilitarized zone because of the Versailles Treaty. -From 1919, Germany wanted to get rid of this zone because it left them open to attack from Belgium, Holland and France. In March 1936, Germany's army occupied the Rhineland.
