Greek word parts

Many words are formed from the Greek word parts logy, meaning “study of”; aster, meaning “star”; therm, meaning “heat”; and sphere, meaning “ball.” Sometimes the Greek word parts are spelled differently when forming an English word, such as astronomy. This word, meaning “study of the stars,”  drops the e from aster and uses astr. 1.    geology 2.    thermometer 3.    astronaut 4.    atmosphere 5.    biology 6.    thermal 7.    disaster 8.    meteorology 9.    technology 10.  hemisphere 11.  zoology 12.  sociology 13.  biosphere 14.  thermos 15.  asterisk 16.  thermostat 17.  astronomy 18.  spherical 19.  ecology 20.  mythology     Challenge Words 21.  psychology 22.  anthropology 23.  thermoelectric 24.  astronomical 25.  microbiology