A—controlled by a computer B—group teaching function C—power supply D—teacher’s monitor function E—to operate with keyboard, light pen or mouse F—recording listening function G—group discussion button H—program selection I—intercom with one student and replay to other students J—speaker output function K—all call and group call with program auto-stopping L—auto memorizing, displaying and clearing M—CRT displays all teaching functions N—teacher’s program dubbing function O—frequency response function P—power consumption ______用键盘、光笔、鼠标操作 ______自动记忆、显示、清除