Practice 3
Writing Based on Reading and ListeningDirections
　　For this task, you will read a passage about an academic topic and you will listen to a lecture about the same topic. You may take notes while you read and listen.
　　Then you will write a response to a question that asks you about the relationship between the lecture you heard and the reading passage. Try to answer the questions completely as possible using information from the reading passage and the lecture. The question does not ask you to express your personal opinion. You may refer to the reading passage again when you write. You may use your notes to help you answer the question.
　　Typically, an effective response will be 150 to 225 words. Your response will be judged on the quality of your writing and on the completeness and accuracy of the content.
　　You should allow 3 minutes to read the passage. Then listen to the lecture. Then allow 20 minutes to plan and write your response.
　　Write your response in the space provided.

[Reading]
　　You will have 3 minutes to read the passage.
　　The jet stream is an irregular band of wind that occurs in high altitudes at about 20,000 feet, that is, between 6 and 9 miles above the surface of the Earth. Consequently, the jet stream wanders near the top of the Earth’s troposphere and coincidentally, that is exactly where most of the Earth’s weather patterns occur. It is helpful to think of the jet stream like a river of air that occurs at several different locations, but in general flows from west to east over the middle latitudes, Technically, to be called a jet stream, the winds should be moving faster than 57 miles an hour, but it can have average core speeds of 190 miles per hour, and in the winter, when the jet stream is strongest, winds have been docked at 300 miles an hour. For the most part, the winds are stronger in the winter because during the winter months the surface temperature contrasts more with the temperature in the troposphere. To put that another way, the greater the contrast in the temperature of the Earth and the atmosphere, the stronger the jet stream winds will blow.
　　In general, there are two jet streams between the equator and the North Pole. The subtropical jet stream tends to hover around the southern border of the continental United States, whereas the polar jet stream blows over Idaho and Montana. The condition that causes these two streams is the difference in the temperature between the tropic and the arctic regions of the Earth, which tends to concentrate in small zones called fronts. It is along these fronts that storms tend to develop. The jet streams blow the storms along their path. When the jet stream is over an area, strong storms may move into it, but when the jet stream has dipped out of the area, dam, dry weather will provably be forecast.
Then you will hear:

Now listen to part of a lecture on the topic you just read about.
[Lecture]
[Essay Topic]
　　Describe jet streams by using the information in the reading, and provide examples of the way that they affect air travel by drawing on the material that you heard in the lecture.
　　You must finish your answer in 20 minutes.