1. A system for generating a ‘snapshot’ of a learning object, comprising: an interface, receiving: a target object, corresponding to a category, comprising a plurality of sentences and multimedia data, wherein the sentences comprise at least one target object keyword; and a user identification number; a learning object database, comprising: a plurality of learning objects, wherein each of the learning objects corresponds to at least one category and comprises at least one learning object keyword; a user's historical learning record, comprising a track record of learning objects used corresponding to the user identification number; and a user keyword input by a user; a script preview unit, selecting at least one of the sentences of the target object as a preview sentence according to the user's historical learning record corresponding to the user identification number, the script preview unit performing steps of: calculating the amount of information contained in the plurality of sentences of the target object; which includes: calculating a relationship matrix of the plurality of sentences in the target object, wherein the relationship matrix comprises a relationship value for each pair of the plurality of sentences; and calculating a sum of the relationship values of each of the plurality of sentences and other sentences of the plurality of sentences as a value specifying the amount of information thereof; selecting at least one pertinent keyword relating to the target object from the plurality of learning objects according to the user's historical learning record corresponding to the user identification number; and selecting the sentence, among the plurality of sentences, that contains the largest amount of information and the user keyword or the pertinent keyword as the preview sentence; a multimedia preview unit, selecting one of the multimedia data of the target object as a preview multimedia data, wherein the selected multimedia data is highly related to the selected sentence; and a ‘snapshot’ generator, generating a ‘snapshot’ of the target object by combining the preview sentence and the preview multimedia data, and directing a display device to display the ‘snapshot’.