Where does carbon dioxide and oxygen exchange take place?

Which of the following is a possible reason for sleep? a) growth b)digestive c)speed d)intelligence

Texas has an impending storm, and california is experiencing a water crisis. match the technologies with the state that can use them to reduce the effects eddies natural hazards. texas is the storm cellar and the wood that is crisscrossed. california is the dam and the storage tanks

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