Which of the following is a secondary pollutant?

What are the four basic classes of organic molecules how do they differ structurally and functionally

Name the types of burns one can get and which structures of the integument are damaged

The ancestors of plants that lived in water had plenty of water for the young. angiosperms are a group of land plants that evolved a reproductive trait for living on land. this trait protect young plants by allowing them to grow only when water is present and the conditions for healthy development are right. what trait most likely young angiosperms in this way?