Media Pool Issue

This is really basic so please accept opologies. I place about 100 images and videos into media pool to create a slide show. I start coping them into the timeframe. however the media pool doesn't show which files have already been used. this means that I'm constantly hunting for images and deleting duplicates in the time line. is there a way for media pool to showing the files already dropped into the timeline?

The Media Pool provides a Usage column. Right click the column header and check the Usage option in the contextual menu.

The Media item's contextual menu within the Media Pool includes a "Usage" sub-menu which indicates the Media item's usage on the Timeline with corresponding Timecode entries.

When you're in Thumbnail View, there is a red line at the bottom of the clip's thumbnail indicating which sections of that clip are used in the currently active timeline.

The two vertical white lines (should you have them) indicate the currently set In/Out points for that clip.