When eyjafjallajökull erupted in march 2010, ash plumes drifted southeast over europe and, as a result, the controlled airspaces over many european countries were closed to air traffic, stranding thousands of people worldwide. why would flying a commercial jet through a cloud of volcanic ash be dangerous?

According to the statement "when eyjafjallajokull erupted in March 2010, ash plumes drifted southeast over Europe and, as a result, the controlled airspaces over many European countries were closed to air traffic, stranding thousands of people worldwide." The reason why flying a commercial jet through a cloud of volcanic ash would be dangerous are the ash impairs visibility, clogs engines, and abrades engine parts.

i think the answer is c, rivers.

explanation:

sometimes, borders fall along natural boundaries like rivers or mountain ranges. for example, the boundary between france and spain follows the crest of the pyrenees mountains. for part of its length, the boundary between the united states and mexico follows a river called the rio grande. the borders of four countries divide africa’s lake chad: niger, chad, cameroon, and nigeria.

lincoln presided over the union victory in the american civil war, which dominated his presidency. a former whig, lincoln ran on a political platform opposed to the expansion of slavery in the territories. his election served as the immediate impetus for the outbreak of the american civil war.