In the mathematical modeling of industrial robots, forearms can be expressed by commonly used normal length and torsion angle parameters. According to the relevant public information, in the mathematical modeling of industrial robots, which parameters can indicate that the forearm is a multiple-choice question? The options are A normal length and included angle, B normal distance and twisted angle, C normal length and twisted angle, D normal included angle and distance, C normal length and twisted angle. This is a multiple-choice question. Data modeling refers to the abstract organization of all kinds of data in the real world, determining the scope of the database and the organization form of the data until it is transformed into a real database.