Fill in the correct words for biology

Which statement best describes a keystone species? o a. it has littlelmenetic variation. it has an extremely high population. 0 b. 0 c. it remains unaffected by all environmental changes. od. it has a strong influence on the ecosystem. 0 e. it's the first species to populate a new ecosystem.

Type the correct answer in each box. use numerals instead of words. if necessary, use / for the fraction bar. the following chemical equation shows the combustion of ethane. balance the equation by filling in the coefficients. c2h6 + o2 → co2 + h2o

Natural resources are any materials that humans obtain from the earth to meet our wants and needs.