→entertainment×finding_information×assembling_information×(4.1.1.1)_entertainment_is_out_of_scope×(4.1.1.2)_is_the_purpose_to_obtain_information?×(4.1.1.3)_history_of_information_transmission×(4.1.1.4)_assemble_one-dimensional_information_in_the_brain×(4.1.1.5) Only the content of the book is not a box to build understanding×(4.1.1.6)_gradation_between_"finding"_and_"assembling"→