I think it’s both ice cores and tree rings
D.The Egyptians could not build roads, and therefore they had to depend on the Nile river for transportation.
Washington Gladden's ideas would most closely be tied to the period in U.S. history that begins just after the Civil War and leads into Reconstruction.
China and Japan are geographically separated only by a relatively narrow stretch of ocean. China has strongly influenced Japan with its writing system, architecture, culture, religion, philosophy, and law. When Western countries forced Japan to open trading in the mid-19th century, Japan moved towards modernization (Meiji Restoration), viewing China as an antiquated civilization, unable to defend itself against Western forces in part due to the First and Second Opium Wars along with Anglo-French Expeditions from the 1840s to the 1860s. Japan's long chain of invasions and war crimes in China between 1894 and 1945 as well as modern Japan's attitude towards its past are major issues affecting current Sino-Japanese relations.