What is the default maximum number of MFA devices in use per AWS account (at the root account level)?

In order to optimize performance for a compute cluster that requires low inter-node latency, which of the
following feature should you use?

When you resize the Amazon RDS DB instance, Amazon RDS will perform the upgrade during the next
maintenance window. If you want the upgrade to be performed now, rather than waiting for the maintenance
window, specify the _____ option.

You run an ad-supported photo sharing website using S3 to serve photos to visitors of your site. At some point
you find out that other sites have been linking to the photos on your site, causing loss to your business. What is
an effective method to mitigate this?

A __________ is a document that provides a formal statement of one or more permissions.

Per the AWS Acceptable Use Policy, penetration testing of EC2 instances:

Through which of the following interfaces is AWS Identity and Access Management available?

Which Amazon storage do you think is the best for my database-style applications that frequently encounter
many random reads and writes across the dataset?

If I want my instance to run on a single-tenant hardware, which value do I have to set the instance’s tenancyattribute to?

Will I be charged if the DB instance is idle?