Change the background without interruption, direct right mouse click on the background you want to switch

Select the slide show to switch

Change the way to set their own time, without interruption you need to set the background you want to automatically all the time of the time.

Music uninterrupted, in the music playback interface, above the insert sound, select the file of music

then click on the automatic, in the click on the speaker right-click to select the edit sound object,

click on the loop playback know stop.