Please explain me what is quality assurance and which technologies do I need to know?

Answer the car to the left must yield the right of way to the vehicle on the right;

Placeholders  are the containers in  layouts  that hold such content as  text  (including body  text, bulleted lists, and titles),  tables,  charts, smartart graphics, movies, sounds, pictures, and clip art.  slide layouts  also contain the theme (colors, fonts, effects, and the background) of a  slide.