What do risk burn down graphs show?

Drag and Drop Question
Match the time box to the Scrum meeting for a one-month Sprint.

What Scrum event or artifact is the single source of requirements for any changes to be made to the product?

During a project meeting, a team is faced with a difficult decision. After discussion and deliberation, the project leader makes the final decision and ends the discussion. This causes a team member to withdraw from future collaboration.
How could the project leader have avoided this?

In Agile development, what is the term for the internal things that you choose not to do now, knowing they will impede future development if left undone?