Masks worn during experiments with plague. Manila, Philippines (1912). Original image from National Museum of Health and Medicine. Digitally enhanced by rawpixel.
Nuclear power plant. Free public domain CC0 photo.
Social Media Mix 3D Icons | Foto: howtostartablogonline.net | via Flickr.com
Buying lettuce in a grocery store. Via Rawpixel
Doctor hands analyzing Coronavirus COVID 19 test blood Foto: Marco Verch | ccnull.de | CC-BY 2.0