A good introductory activity for NGSS.5-ESS2-1, this online, self-checking, activity starts by introducing the four spheres of Earth: geosphere, hydrosphere, atmosphere, and biosphere. Students then identify which sphere can be seen in a series of photos, answer multiple choice and fill-in-the-gap questions based on the information they've been given, as well as stretch their vocabulary by identifying the meanings of other words using the same prefixes. Far more colorful and engaging than a phot