Yes you can! Follow the steps below:
- Position your cursor where you wish to add the slides into your new presentation, then click the Insert tab.
- On the ribbon, click the drop-down arrow on New Slide button and choose Reuse Slides.
- A navigation pane opens to the right. Click the Browse button and choose Browse file... to locate the presentation containing the slides you want to insert.
- Highlight the presentation from the list of files and click Open.
- The Reuse Slides pane now displays the slides from the presentation as thumbnails.
- To insert a slide, click the thumbnail of the slide.
- To keep the slide's original background, check the box for Keep Source Formatting.
- When you have inserted all the slides needed, click the "X" at the top, right-hand corner of the Reuse Slides pane to close it.