When an IPsec communication begins between two computers, the computers first exchange ____ to authenticate the receiver and sender.

As shown in the accompanying figure, XML Schema supports ____ types of content.

A. two B. three C. four D. six

When you create a table like the one in the accompanying figure, Dreamweaver inserts a(n) ____ in each cell.

A. break tag B. nonbreaking space C. hyperlink D. anchor tag