Word Unit: Having a Good Vocabulary (understanding how English words are formed and where they come from helps everyone who finds unfamiliar words)

Word Unit: Health Care Providers, Health-Care Providers, Healthcare Providers (medical professionals and scientists who specialize in designated areas of medical care)

Word Unit: Hedgerows (fields are protected by barriers of hedges by keeping the wind from eroding (blowing away) valuable top soil)

Word Unit: Herodotus, The Fifth-Century B.C. Greek Traveler and Historian (Herodotus extended his historical coverage beyond the Greek world to the lives, ways, and beliefs of the people with whom the Greeks and the Persians came into contact)

Word Unit: Hydrology (the science of water which denotes the study of the properties, distribution, and movements of water on land surfaces, in the soil, and through the subsurface rocks of the earth)

Word Unit: Hydroponics: Soilless Production of Crops (a description in which plants can be produced in containers filled with water and a number of other non-soil contents)

Word Unit: Hyphen - (hyphens as punctuation marks)