In this task, you will be presented with a context passage, a question about that paragraph, and a possible answer to that question. The task is to check the validity of the answer. Answer with "Yes" or "No".

You know that friction also causes heat. Think about when you rub your hands together. It is friction that makes them warm. But why does this happen? Friction causes the molecules on rubbing surfaces to move faster. Faster moving particles have more heat energy. Heat from friction can be useful. Can you think of other places where you might find friction? Friction also lets you light a match. Heat from friction can also cause problems. It can cause a car to overheat. To reduce friction, oil is added to the engine. Oil coats the surfaces of moving parts. This coating of oil makes them slippery. When things are slippery there is less friction. Have you ever seen a sign that says, slippery when wet? This too has to do with friction. Water, like oil, can reduce friction. The wet surface may allow your shoes to slide more easily. <sep>What can be done to prevent friction problems in engines?<sep>Oil is added to the engine
Yes

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. <sep>What source of money did bin Laden hold in Sudan?<sep>A family company
No

Even though electronic espionage may cost U.S. firms billions of dollars a year, most aren't yet taking precautions, the experts said. By contrast, European firms will spend $150 million this year on electronic security, and are expected to spend $1 billion by 1992. Already many foreign firms, especially banks, have their own cryptographers, conference speakers reported. Still, encrypting corporate communications is only a partial remedy. One expert, whose job is so politically sensitive that he spoke on condition that he wouldn't be named or quoted, said the expected influx of East European refugees over the next few years will greatly increase the chances of computer-maintenance workers, for example, doubling as foreign spies. Moreover, he said, technology now exists for stealing corporate secrets after they've been "erased" from a computer's memory. He said that Oliver North of Iran-Contra notoriety thought he had erased his computer but that the information was later retrieved for congressional committees to read. No personal computer, not even the one on a chief executive's desk, is safe, this speaker noted. W. Mark Goode, president of Micronyx Inc., a Richardson, Texas, firm that makes computer-security products, provided a new definition for Mikhail Gorbachev's campaign for greater openness, known commonly as glasnost. Under Mr. Gorbachev, Mr. Goode said, the Soviets are openly stealing Western corporate communications. He cited the case of a Swiss oil trader who recently put out bids via telex for an oil tanker to pick up a cargo of crude in the Middle East. Among the responses the Swiss trader got was one from the Soviet national shipping company, which hadn't been invited to submit a bid. The Soviets' eavesdropping paid off, however, because they got the contract. <sep>Who did the Soviets contract with to pick up a cargo of crude oil in the Middle East?<sep>Israeli Oil Trader
No