(topic learningBase+learningInteractionBase-d) The <learningBase> element is the top-level element for learningBase. The <learningBasebody> element is the main body-level element inside a learningBase topic. The <lcIntro>) section... The <lcObjectives>) section... The <lcObjectivesStem>) section... The <lcObjectivesGroup>) section... The <lcObjective>) section... The <lcAudience>) section... The <lcDuration>) section... The <lcTime>) section... The <lcPrereqs>) section... The <lcSubject>) section... The <lcAuthorInfo>) section... The <lcSummary>) section... The <lcNextSteps>) section... The <lcInteraction>) section... The <lcReview>) section... The <lcResources>) section... The <lcChallenge> element is... The <lcInstruction> element is...