① opens the "insert"-> Sound "->" file sound, insert the prepared sound file (MP3 or WAV, etc., and now insert the words "you are going to marry me today. mp3");
② the system pops up a dialog box asking "How do you want the sound to start when the slide is playing", and click Auto to play the sound when the slide is displayed, with a "horn" icon appearing on the slide;
③ Click to select the "Horn" icon, select "Animation"-> "Custom Animation";
④ Click the Custom Animation dialog box on the right side of the window "You are going to marry me today." MP3 The right Drop-down arrow, select Start from Previous, and then click Effect Options;
⑤ on the Effect Options setting page, the default option for stop playing is [when clicked]. Depending on your needs, if you want the background music to exist on the "X" Slide, select "After x slides" in the "Stop playing" option, where x represents the number of slides you want the background music to persist.
If you want to add full background music, just insert the music file on the first slide and change the "X" after the "stop playing" option to the total number of slides.
Similarly, you can insert different background music at different stages of the slide, such as the 1th to 10th one with the background music "love you 10,000 Years." MP3, 11th to the last with the background music "The Moon Represents My Heart." MP3.