Answer:
ExplanationThe three-age system is the periodization of history into three time periods;[1][better source needed] for example: the Stone Age, the Bronze Age, and the Iron Age; although it also refers to other tripartite divisions of historic time periods. In history, archaeology and physical anthropology, the three-age system is a methodological concept adopted during the 19th century by which artifacts and events of late prehistory and early history could be ordered into a recognizable chronology. It was initially developed by C. J. Thomsen, director of the Royal Museum of Nordic Antiquities, Copenhagen, as a means to classify the museum's collections according to whether the artifacts were made of stone, bronze, or iron.
The radioactive materials released by the accident had many immediate harmful effects on plants and on living things such as nature and animals within 20 to 30 km of the Chernobyl power plant at the time of the accident.
Answer:
Letter D
Explanation:
Formality. The practice arises from a duty of the President under the State of the Union Clause of the U.S. Constitution: He shall from time to time give to Congress information of the State of the Union and recommend to their Consideration such measures as he shall judge necessary and expedient.
