National parks can be a double-edged sword because it often costs too much to visit them the crowds of people that are attracted can disrupt the ecosystem the parks are not necessarily interesting they do not generate any revenue

the crowds of people that are attracted can disrupt the ecosystem.

National parks can be a double-edged sword because the people that come visit them can often disrupt the ecosystem. This defeats the original purpose, as national parks are established in order to protect the ecosystem from the damage of humans. However, some measures can be taken in order to reduce the damage. For example, crowds can be reduced by introducing daily limits, or increasing the price of tickets. Security can be increased in order to monitor the crowds. Finally, reminding the crowds of the fragility of the parks can sometimes improve the people's behaviour.

for many centuries there were important factors which the economies of the muslim empires developed increasingly. they applied economic procedures in production, investment, finance, taxation and property. they used to tax certain goods (for example: harvest), they charged interest on money lent, they signed contracts with merchants; they relied on a common currency, and they used checks as well as promissory notes. with the money collected by means of taxation, the government provided the needy with an income. in addition, trading networks covered huge distances, so far regions started to have contact and exchange goods. this trade network covered areas of asia, africa and europe.