Which of the following is not true about nonnative species? a. they can have positive impacts on an ecosystem. b. they can have negative impacts on an ecosystem. c. they can be introduced within their natural range. d. a nonnative species can be an invasive species.

Which statement describes a way in which the digestive and excretory systems work together? a. the nephrons absorb nutrients from food going to the large intestine. b. the excretory system balances blood gases in the small intestine. c. the intestinal villi filter blood and send wastes to the bladder. d. the excretory system balances the salts and water obtained from digested food