Answer:
B. four-crop rotations
Explanation:
the four-crop rotations was invented in the 18th century which means from January 1, 1701 to December 31, 1800. (1700s).

The Correct choice is : C. <u>Solids</u>
Sound waves need a medium to propagate, and the most suitable medium for that is solids, where it travel the fastest or with greatest efficiency.
Answer:
More developed countries (MDCs) are located mainly in North America (Anglo-America) and East and West Europe (additional: Japan & South Pacific).
Least developed countries (LDCs) are located mainly in Latin America, East and South Asia, Southeast Asia, Southwest Asia/North Africa, and pretty much the whole of frican Africa is considered one big LDC. Africa is pretty much a continent of LDCs.
Answer:
Ocean currents, air currents, rotation of the earth.
Explanation:
ocean currents can effect the temperature of the water. air currents can bring in dry warm air, like over Africa and help warm the sea more, or cooler air from the arctic to help cool the surface water. Many of these effect are driven by the Coriolis Effect.