PASSAGE 2 – Questions 11–20

Floods are second only to fire as the most common of all natural disasters. They occur almost everywhere in the world, resulting in widespread damage and even death. Consequently, scientists have long tried to perfect their ability to predict floods. So far, the best they can do is recognize the potential for flooding in certain conditions. There are a number of causes, from deep snow on the ground to human error.

The first cause of flooding is deep snow on the ground. When deep snow melts, it creates a large amount of water. Although deep snow alone rarely causes floods, when it occurs together with heavy rain and sudden warmer weather, it can lead to serious flooding. If there is a fast snowmelt on top of frozen or very wet ground, flooding is more likely to occur. Frozen ground or ground already saturated with water cannot absorb the additional water created by the melting snow. Melting snow also contributes to high water levels in rivers and streams. Whenever rivers are already at their full capacity, heavy rains will cause them to overflow and flood surrounding land.

Secondly, rivers that are covered in ice can also lead to flooding. When ice begins to melt, the surface cracks and breaks into large pieces. These pieces of ice move and float down the river. They can form a dam, causing the water behind it to rise and flood upstream land. If the dam breaks suddenly, the large amount of water held behind it can flood areas downstream as well.

Broken ice dams are not the only dam problems that cause flooding. Those carelessly constructed by humans can also result in floods. When a large human-made dam breaks or fails to hold the water behind it, the results can be devastating. Dams contain such huge amounts of water that when sudden breaks occur, the destructive force is like a great tidal wave. Unleashed dam waters can travel tens of kilometres, cover the ground in metres of mud and debris, and destroy everything in their path.

Although scientists cannot always predict exactly when floods will occur, they know a great deal about when floods are likely to happen. Deep snow, ice-covered rivers, and weak dams are all strong conditions for potential flooding. Hopefully, this knowledge of why floods happen can help reduce the damage they cause.

11. What is the most common natural disaster?

PASSAGE 3 – Questions 21–30

Musical Talents

Among all the abilities with which an individual may be endowed, musical talent appears earliest in life. Very young children can exhibit musical precocity for different reasons. Some develop exceptional skill through a well-designed instructional regime, such as the Suzuki method for the violin. Others are born into musical families in households filled with music. In some cases, musical talent is part of an otherwise disabling condition such as autism or mental retardation. A musically gifted child has an inborn talent; however, the extent to which that talent is expressed publicly depends upon the environment in which the child lives.

Musically gifted children master at an early age the principal elements of music, including pitch and rhythm. Pitch—or melody—is more central in certain cultures, for example, in Eastern societies that make use of tiny quarter-tone intervals. Rhythm, or sounds produced at specific auditory frequencies and grouped according to a system, is emphasized in sub-Saharan Africa, where the rhythmic ratios can be very complex.

All children have some aptitude for making music. During infancy, normal children sing as well as babble, and they can produce individual sounds and sound patterns. However, individual differences begin to emerge as they learn to sing. Some children can match large segments of a song by the age of two or three. Many others can only approximate pitch at this age and may still have difficulty producing accurate melodies by the age of five or six. By the time they reach school age, most can reasonably imitate songs commonly heard in their environment.

The early appearance of superior musical ability in some children provides evidence that musical talent may be a separate and unique form of intelligence. There are numerous tales of young artists who have a remarkable or extraordinary memory for music and a natural understanding of musical structure. In many cases, the child is average in every other way but displays exceptional ability in music. Even the most gifted child, however, takes about ten years to achieve the level of performance or composition that would constitute mastery of the musical sphere.

Every generation in music history has had its famous prodigies—individuals with exceptional musical powers that emerge at a young age. In the eighteenth century, Wolfgang Amadeus Mozart began composing and performing at the age of six. As a child, Mozart could play the piano like an adult. He had perfect pitch, and by nine he was already a master of modulation—the transition from one key to another—which became one of the hallmarks of his style. By the age of eleven, he had composed three symphonies and thirty other major works. Mozart’s well-developed talent was preserved into adulthood.

21. The word precocity in paragraph 1 is closest in meaning to

PASSAGE 4 – Questions 31–40

The UH-1 Helicopter: Icon of the Vietnam War

Every modern war has its icon — the technological development essential to the conflict, the one that changes the course of battle and becomes symbolic of the time. The Civil War’s was the cannon, World War I’s the machine gun, and World War II’s the tank. Each left its mark on the landscape and the soldier. Vietnam’s icon was the helicopter — specifically the UH-1 utility helicopter, known to soldiers as the “Huey.”

The geographic and political realities of Vietnam called for a new kind of warfare, one the U.S. Army termed “Airmobile.” Remote battle zones, mountain jungles, and undeveloped roads eliminated motor vehicles as a means of moving troops and supplies quickly. Helicopters took over. In Airmobile warfare, flocks of helicopters transported troops and supplies to strategic locations, monitored operations from the air, engaged in battle, and evacuated forces. The famed U.S. Army 1st Cavalry joined aviation units already in Vietnam to pioneer Airmobile operations, trading its horses for helicopters and creating a model followed by the 101st Airborne, the 1st Aviation Brigade, and other aviation units.

Many helicopters were used in Vietnam, but none was as widely employed as the Huey. The UH-1 “Iroquois,” popularly called the Huey, became the “workhorse” of the war. Used by all military forces for troop transport, medical evacuation, and combat assault, Hueys carried soldiers and supplies to the front lines as the horses of a modern cavalry. The U.S. Army and Marine Corps also made them into gunships by adding machine guns and rocket pods for frontal assaults. Hueys carried officers for planning, soldiers to battle, nurses to orphanages, and “Donut Dollies” to entertain troops. Outfitted with loudspeakers, they also broadcast Psychological Operations (PSYOPS) messages.

Perhaps most significantly, Hueys were the technology behind “Dustoff” — the evacuation of the wounded, so named by a pilot who gave his life doing it. The ability to swoop into battle, load the Huey with wounded, and fly them to hospitals — first developed in Korea and perfected in Vietnam — has been called one of the major medical innovations of the war. This quick transport meant that over 90 percent of wounded soldiers who reached a medical facility survived. The evacuation techniques learned from the Huey later evolved into the modern air-rescue systems we rely on today. The Huey was also remarkably versatile, easily modified for various missions. Its interchangeable interiors allowed conversion from troop carrier to air ambulance. It was capable of flying under extreme stress and allowed rapid entry and exit — crucial for extraction and rescue missions. Those who flew and maintained them remain fiercely loyal to the Huey, even after piloting many other aircraft.

More than 7,000 Huey helicopters served in Vietnam, and nearly half were lost. Some 2,177 Huey crew members were killed in action. Because the Huey was always there for them, the distinctive “WHOP WHOP” of its 48-foot rotor blades slapping the air became, for soldiers on the ground, the sound of their lifeline.

31. What is the best synonym for the word icon as it is used in the first paragraph?