10 free HiSET practice questions in the real exam format, covering the official content areas, with an explanation for every answer.
HiSET Practice Test 8Tutor mode
Question 1 of 10
Science
Lichens are organisms that grow on tree bark and are harmed by sulfur dioxide, an air pollutant released by burning coal. Ecologists counted the number of lichen species growing on trees at six sites, each a different distance from the center of an industrial city.
Between which two neighboring sites did the number of lichen species change the least?