Answer: The federal government owns roughly 640 million acres, about 28% of the 2.27 billion acres of land in the United States. Four major federal land management agencies administer 606.5 million acres of this land (as of September 30, 2018). They are the Bureau of Land Management (BLM), Fish and Wildlife Service (FWS), and National Park Service (NPS) in the Department of the Interior (DOI) and the Forest Service (FS) in the Department of Agriculture. A fifth agency, the Department of Defense (excluding the U.S. Army Corps of Engineers), administers 8.8 million acres in the United States (as of September 30, 2017), consisting of military bases, training ranges, and more. Together, the five agencies manage about 615.3 million acres, or 27% of the U.S. land base. Many other agencies administer the remaining federal acreage.
Explanation: Pursuant to the Property Clause of the United States Constitution (Article 4, section 3, clause 2), the Congress has the power to retain, buy, sell, and regulate federal lands, such as by limiting cattle grazing on them.
The answer is obviously “A”
US: 40 degrees N
China: 30 degrees N
I believe C is the right anwser
Answer:
The use of the abacus was expanded and refined.
Explanation:
The abacus was invented during the Yuan Dynasty which lasted between 1206AD till 1368AD and then it was expanded and refined by the Ming Dynasty (1368AD-1644AD).
There have been archaeological proof of this as the writings of Tao Zongyi describes in his book that the new servants, unlike the older and more experienced ones were "just like abacus heads" and that they would not move unless they were made to move. This bears credence to the fact that the abacus was already widely used then.
An abacus was used to count numbers.