Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions

It’s a sound you will probably never hear, a sickened tree sending out a distress signal. But a group of scientists has heard the cries, and they think some insects also hear the trees and are drawn to them like vulture to a dying animal. Researchers with the US Department of Agriculture’s Forest Service fastened sensors to the bark of droughtstricken trees clearly heard distress calls. According to one of the scientists, most parched trees transmit their plight in the 50-hertz to 50-kilohertz range. (The unaided human ear can detect no more than 20 kilohertz). Red oak, maple, white pine, and birch all make slightly different sounds in the form of vibrations at the surface of the wood. The scientists think that the vibrations are created when the water columns inside tubes that run along the length of the tree break, a result of too little water following through them. These fractured columns send out distinctive vibration pattems. Because some insects communicate at ultrasonic frequencies, they may pick up the trees' vibration and attack the weakened trees. Researchers are now running tests with potted trees that have been deprived of water to see if the sound is what attracts the insects. “Water-stressed trees also smell differently from other trees, and they experience thermal changes, so insects could be responding to something other than sound”, one scientist said. 

All the following are mentioned as possible factors in drawing insects to weakened trees EXCEPT .............

According to the passage, which of the following is true?

Why does the author mention Lady Gaga?

The article is mainly about.......... 

As a result of pollution, Lake Erie, on the borders of the USA and Canada, is now without any living things. Pollutions in water are not simply a matter of “poisons” killing large numbers of fish overnight. Very often the effects of pollution are not noticed for many months or years because the first organisms to be affected are either plants or plankton. But these organisms are the food of fish and birds and other creatures. When this food disappears, the fish and birds die in this way a whole food chain can be wiped out, and it is not until dead fish and water birds are seen at the river’s edge or on the sea shore that people realize what is happening. Where do the substances which pollute the water come from? There are two main sources – sewage and industrial waste. As more detergent is used in the home, so more of it is finally put into our rivers, lakes and seas. Detergents harm water birds dissolving the natural substance which keep their feather waterproof. Sewage itself, if it is not properly treated, makes the water dirty and prevents all forms of life in rivers and the sea from receiving the oxygen they need. Industrial waste is even more harmful since there are many high poisonous things in it, such as copper and lead. So, if we want to stop this pollution, the answer is simple, sewage and industrial waste must be made clean before flowing into the water. It may already be too late to save some rivers and lakes, but others can still be saved if the correct action is taken at once. 

According to the passage, the way to stop water pollution is ...........

Which statement would the author probably agree with?

Facebook ............... 

THE PEOPLE BEHIND THE MUSIC Think for a moment about the last music album you bought. Most likely, you’ll think of the singer or band that made you want to buy the album. You might even know the name of the guitar player or the drummer. Those talented performers, however, are only some of the people in the music industry work behind the scenes, but the roles they play in the musical progress are very important. Songwriters: Songs begin with the songwriter. Some songwriters work alone, but many work in teams that combine the talents of a lyricist, who writes the words to songs, and an instrumentalist, often a piano player or guitarist, who writes the music. Many of today’s pop stars work with songwriters. For example, some of Lady Gaga’s biggest hits were written by Nadir Khayat, also known “RedOne”. Some songwriting teams have become very famous, such as Mike Stock, Matt Aitken, and Pete Waterman, who were responsible for many big 1980s pop hits. Arrangers: After a song has been written, music arrangers make it more appealing by deciding which instruments will be used, what tempo, or speed, the song will have, and whether the song should have a lower or higher pitch. A good arrangement can bring a song to life and make it a classic. Studio Musicians: Not every singer or instrumentalist can be a star, and many work in the background as studio musicians. These artists are not a part of any one musical group. Instead, they are hired for recording sessions that eventually become the albums you buy, as well as soundtracks for television shows, movies, and radio ads. Recording Engineers: Recording engineers also play a major role in creating the final sound that you hear. First, these engineers set up the recording studio, the room where the performers play, placing musicians and microphones in exactly the right places to get the best sound. Next, they use electronic equipment, such multi-track recorders, to capture the music. Finally, long after the musicians have gone home, recording engineers use a mixing board to balance the melodies and rhythms of each musician, and sometimes to incorporate special sound effects or additional tracks. Many people make a living with music. You may not recognize all of their names, but all of them work together to create the songs you love to listen to. 

Which piece of equipment is used at the end of the recording process?