Standard user accounts can NOT clean up other people's files using Disk Cleanup

If you have a frameset nested within a second frameset that is nested within a third frameset and so on, you can access any frame you want by developing the proper sequence of ____ objects.

A. JavaScript parent B. JavaScript child C. JavaScript key D. JavaScript parameter

? Microblogging websites group related messages by _________________________, as shown in the accompanying figure.

Fill in the blank(s) with the appropriate word(s).