Which statement best describes a human influence on the biogeochemical cycles?
increased eutrophication caused by high levels of nitrogen and phosphorous
increased nitrates available due to inaccurate methods of denitrification
increased global warming due to alternative energy sources
increased amount of water that is available to freshwater ecosystems

Ineed to know why d is the correct answer asap

According to piaget, children have acquired the cognitive skill of conservation when they're able to a. understand that six ounces of liquid in a jar and six ounces in an elongated tube are equal. b. understand the viewpoint of other people. c. relate objects around them to their own needs. d. realize that the term heavy describes an object one way and the term big describes it another way. it is not b nor c. did this 2 x wrong..

The transport tubes from food came down the plant are called?