Please help me I don't understand

List two modern organisms that have pentameral symmetry

Which best describes the scientific method? a. a path of clearly defined steps that must be followed in a particular order b. a possible answer to a scientific question based on knowledge or research c. the recipe for how to conduct an experiment that must be followed precisely d. the process of hypothesis and testing through which scientific inquiry occurs

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