Complex sentence: Glass fever thermometers typically have markings every 0.1 ° C or 0.2 ° F. Basal temperature is stable enough to require accuracy of at least 0.05 ° C or 0.1 ° F, so special glass basal thermometers are distinct from glass fever thermometers.
Split into simpler sentences: Glass fever thermometers typically have markings every 0.1 ° C (0.2 ° F). Basal thermometers require accuracy of at least 0.05 ° C (0.1 ° F), so special glass basal thermometers are sold separately from glass fever thermometers.