20 Educational Slide Photos Needed

I’m finalising a 20-slide educational deck and now need the visuals to pull everything together. The copy and layout are done; your task is to source twenty high-impact photographs that match the message of each slide.

Deliverables
• 20 photographs named Slide 1–Slide 20, 16:9 ratio, minimum 1920×1080 resolution
• Source URL or licence free for each image
• One-page contact sheet (PDF) showing all selections at a glance