Once a person is affected by a dengue virus, the platelets can no longer âactivateâ itself. So whenever there is damage, the platelets cannot form the mesh structure and the blood flows out of the vessel. As blood flows out, so does the platelets. This causes the platelet count to fall drastically. The blood that flows out causes internal. and external bleeding and leads to a haemorrhage.
1 Today, the Aswan Dam keeps the Nile from flooding modern cities. 2  The Ancient Egyptians called the Nile the Aur, which means black and comes from the black soil. 3  The Egyptians measured the height of the annual flood using a Nilometer.
Without the Nile River, all of Egypt would be desert. Only about an inch (2.5 centimeters) of rain falls throughout Egypt each year. But each summer, the river rises because of rains at its source far to the south in Ethiopia. Floods cover the river's valleys, leaving sediments needed for trees, plants, and crops to grow.