Why were the nile cataracts a problem for kush? a() their trading boats were unable to go past themb() many soldiers died on themc() they cut kush off of tradingd() the egyptians used them as a defense against kush's armies

There are two answers for this question, BUT, I say D is the best of these two

A. Their trading boats were unable to go past them;

D. The Egyptians used them as a defense against the Kush's armies;

The cataracts on the river Nile are part of the river where the waters are shallow, and there's also lots of rocks that are very close to the surface of the water. This makes them unsuitable for boats and for the Kush that was a big problem. The cataracts were limiting Kush to only perform trade and military actions on land, and Egypt used that advantage to the maximum.

The Nile cataracts can be used for sailing with boats but only when there's flood, so that is only in a very short period of time, and not to mention that when there's flood the waters are very unpredictable and can be fatal.

this statement is true.

forests are public goods, available for everybody. when usage of such a good becomes interesting for consumers and its usage increases, there can be a risk of overexploitation. it is a non rival good therefore, if one person consumes the good it does not reduce the availability for subsequent consumers.

these caracteristics require the establishment of measures in order to prevent the destruction of a commonly owned space, for example, to restrict the amount of people that have access to the same time.