Answer:
Radio-wave communications signals travel through the air in a straight line, reflect off of clouds or layers of the ionosphere, or are relayed by satellites in space. They are used in standard broadcast radio and television, shortwave radio, navigation and air-traffic control, cellular telephony, and even remote-controlled toys.
Explanation:
The correct answer is B) <span>the ruins of mohenjo-dark
</span>Archaeologist study human prehistoric history, by <span>analyzing acient artifacts or other physical remainings</span>
The reason why some of the founders of the American republic considered the lack of a national executive and judiciary under the Articles of Confederation as one <span>of the documents great strenghts is because the favored a weak central government and "strong" individual states--since they were afraid that a strong central government would become tyrannical. </span>
South Sakhalin (prewar-1945)
