Which of the following is an essential amino acid?

Which process of living things produces water that enters the water cycle

Use the phylogenetic tree to the right to determine which statement below is true. organisms a and f are not related. organism e is more closely related to organism b than organism f. organisms c and d are more closely related than organisms a and b. phylogenetic trees

The earth's oceans are made up of chlorine, and trace elements. a) carbon, oxygen b) oxygen, silicon c) hydrogen, oxygen d) nitrogen, oxygen