Final answer:
Tectonic landforms and river valleys are not found on Mercury, Mars, and Earth. Plate tectonics primarily occur on Earth, while Mercury is geologically inactive and Mars does not show current tectonic activity. River valleys are absent on Mercury and not extensively found on Mars.
Step-by-step explanation:
Among Mercury, Mars, and Earth, the geologic features not commonly found on all three planets are tectonic landforms and river valleys. Tectonic landforms, including rift zones, subduction zones, and mountain ranges due to crustal compression, are distinctive features caused by plate tectonics primarily on Earth, because of its active geological interior and the presence of moving crustal plates. Comparatively, Mercury is geologically inactive due to its small size and lack of nearby gravitational interactions that can drive tectonic processes. While Mars shows some signs of past tectonic activity, it does not display currently active plate tectonics like Earth.
River valleys, specifically, are scarce on Mercury and Mars. Mercury lacks an atmosphere and hence could not have supported liquid water to create river valleys. Meanwhile, Mars may have ancient, now-dry river valleys, suggesting past water flow, but these are not active and are not comparable to the extensive network of rivers found on Earth, which is supported by Earth's atmosphere and liquid water on its surface.