For Mac OS users, there is a system setting that may not allow you to tab onto several types of elements in a web page. To change this setting:
SEPTEMBER-Friendship
OCTOBER-Conflict Resolution/Drug Awareness
NOVEMBER-Anti-Bullying
DECEMBER-Cyber Awareness
JANUARY-Social Media part 1
FEBRUARY-Relationship
MARCH-Social Media Etiquette
APRIL-What to know about the next grade level