A flood occurs when a river overflows its banks. This might happen because of heavy rains. Floodplains In very flat regions, flood water may spread out on the surface of the land. It then slows down and drops its sediment. If a river floods often, a floodplain develops. A floodplain is an area where a thick layer of rich soil is left behind as the floodwater recedes. Thats why floodplains are usually good places for growing plants. They are very flat areas and they have very rich soils. The Nile River valley is a great example of a floodplain. Each year, the Nile River rises over its banks. This floodwater carries a lot of sediment. This sediment has been eroded off areas of land from upstream. This sediment is dropped as the water slows down after spreading across the land. What is left behind is a very rich soil. Thats why crops can be raised in the middle of a sandy desert. Natural Levees A flooding river often forms natural levees along its banks. A levee is a raised strip of sediments deposited close to the waters edge.

Question: "What may cause a river to flood and overflow its banks?"

Response: "Upstream erosion"

A: no

Bin Laden and his aides did not need a very large sum to finance their planned attack on America. The 9/11 plotters eventually spent somewhere between $400,000 and $500,000 to plan and conduct their attack. Consistent with the importance of the project, al Qaeda funded the plotters. KSM provided his operatives with nearly all the money they needed to travel to the United States, train, and live. The plotters' tradecraft was not especially sophisticated, but it was good enough. They moved, stored, and spent their money in ordinary ways, easily defeating the detection mechanisms in place at the time. The origin of the funds remains unknown, although we have a general idea of how al Qaeda financed itself during the period leading up to 9/11. General Financing As we explained in chapter 2, Bin Laden did not fund al Qaeda through a personal fortune and a network of businesses in Sudan. Instead, al Qaeda relied primarily on a fund-raising network developed over time. The CIA now estimates that it cost al Qaeda about $30 million per year to sustain its activities before 9/11 and that this money was raised almost entirely through donations. For many years, the United States thought Bin Laden financed al Qaeda's expenses through a vast personal inheritance. Bin Laden purportedly inherited approximately $300 million when his father died, and was rumored to have had access to these funds to wage jihad while in Sudan and Afghanistan and to secure his leadership position in al Qaeda. In early 2000, the U.S. government discovered a different reality: roughly from 1970 through 1994, Bin Laden received about $1 million per year-a significant sum, to be sure, but not a $300 million fortune that could be used to fund jihad. Then, as part of a Saudi government crackdown early in the 1990s, the Bin Laden family was forced to find a buyer for Usama's share of the family company in 1994. The Saudi government subsequently froze the proceeds of the sale. This action had the effect of divesting Bin Laden of what otherwise might indeed have been a large fortune. Nor were Bin Laden's assets in Sudan a source of money for al Qaeda. When Bin Laden lived in Sudan from 1991 to 1996, he owned a number of businesses and other assets.

Question: "What source of money did bin Laden hold in Sudan?"

Response: "Business network"

A: yes

He repeatedly calls on his followers to embrace martyrdom since "The walls of oppression and humiliation cannot be demolished except in a rain of bullets." For those yearning for a lost sense of order in an older, more tranquil world, he offers his "Caliphate" as an imagined alternative to today's uncertainty. For others, he offers simplistic conspiracies to explain their world. Bin Laden also relies heavily on the Egyptian writer Sayyid Qutb. A member of the Muslim Brotherhood executed in 1966 on charges of attempting to overthrow the government, Qutb mixed Islamic scholarship with a very superficial acquaintance with Western history and thought. Sent by the Egyptian government to study in the United States in the late 1940s, Qutb returned with an enormous loathing of Western society and history. He dismissed Western achievements as entirely material, arguing that Western society possesses "nothing that will satisfy its own conscience and justify its existence." Three basic themes emerge from Qutb's writings. First, he claimed that the world was beset with barbarism, licentiousness, and unbelief (a condition he called jahiliyya, the religious term for the period of ignorance prior to the revelations given to the Prophet Mohammed). Qutb argued that humans can choose only between Islam and jahiliyya. Second, he warned that more people, including Muslims, were attracted to jahiliyya and its material comforts than to his view of Islam; jahiliyya could therefore triumph over Islam. Third, no middle ground exists in what Qutb conceived as a struggle between God and Satan. All Muslims-as he defined them-therefore must take up arms in this fight. Any Muslim who rejects his ideas is just one more nonbeliever worthy of destruction. Bin Laden shares Qutb's stark view, permitting him and his followers to rationalize even unprovoked mass murder as righteous defense of an embattled faith. Many Americans have wondered, "Why do 'they' hate us?" Some also ask, "What can we do to stop these attacks?" Bin Laden and al Qaeda have given answers to both these questions.

Question: "Approximately how long after studying in the United States was Sayyid Qutb executed?"

Response: "30years"

A:
no