“…In the context of e-learning, there is no single model for the structured content or for the learner profile, which makes the need for ontology more essential [42]. Recently, ontologies and semantic web have been widely used in ITSs, e.g., represent natural language question into meaningful viewpoint and performing problemsolving without human involvement [43], helping teachers to acquire both linguistic knowledge and practical skills using an ontology of lexical concepts [44], to design a concrete gamebased ITS [45] and so forth.…”