Explanation
Office UI Fabric is Microsoft's official front end framework for building User Interface experiences for Office and Office 365. In simple terms it gives you the look and feel for your component. Moreover, they are open source, mobile responsive and reusable, no need to create from scratch just refer them in your code and start utilizing them.
Microsoft modern SharePoint out of the box webparts are made up these Office UI Fabric framework, so to maintain consistency look and feel as like Office it's better to use these components in our custom SPFx webparts.
Reference:
http://www.sharepointsamples.com/sharepoint-framework-webpart-with-office-ui-fabric-react-component/

Explanation
Graphical user interface, text, application Description automatically generated

Reference:
https://docs.microsoft.com/en-us/azure/active-directory/develop/reference-app-manifest

Explanation
Use delta query to track changes in a resource collection
The typical call pattern is as follows:application begins by calling a GET request with the delta function on the desired resource.
* Microsoft
* The Graph sends a response containing the requested resource and a state token.
Example: Selecting three properties
The next example shows the initial request selecting three properties for change tracking, with default response behavior.
Note: Delta query enables applications to discover newly created, updated, or deleted entities without performing a full read of the target resource with every request.
Reference: https://docs.microsoft.com/en-us/graph/api/user-delta

Overview
This is a case study. Case studies are not timed separately. You can use as much exam time as you would like to complete each case. However, there may be additional case studies and sections on this exam. You must manage your time to ensure that you are able to complete all questions included on this exam in the time provided.
To answer the questions included in a case study, you will need to reference information that is provided in the case study. Case studies might contain exhibits and other resources that provide more information about the scenario that is described in the case study. Each question is independent of the other questions in this case study.
At the end of this case study, a review screen will appear. This screen allows you to review your answers and to make changes before you move to the next section of the exam. After you begin a new section, you cannot return to this section.
To start the case study
To display the first question in this case study, click the Next button. Use the buttons in the left pane to explore the content of the case study before you answer the question. Clicking these buttons displays information such as business requirements, existing environment, and problem statements. If the case study has an All Information tab, n...... that the information displayed is identical to the information displayed on the subsequent tabs. When you are ready to answer a question, click the Question button to ret........ to the question.