Where at least the first step is concerned-detection-some of Danneel's colleagues at Sandia may soon provide real help. Cliff Ho and Bob Hughes have created a novel real-time gas- and water-quality monitoring system, made up of a tiny sensor array and weatherproof casing. Whereas traditional monitoring involves collecting samples of water, gas or soil and sending them for laboratory analysis, which can cost from $100 to $1,000, the new device performs its testing on the site and sends its results-via a computer at a collection station-to an interactive Web site.
“The electronic sniffer is a unique monitor that can be put directly underground-in groundwater or soils where the humidity reaches nearly 100 percent-and detect toxic chemicals at the site without taking samples to the lab,” Ho explains. “It has the capability of detecting in real time undesirable chemicals being pumped into the water supply accidentally or intentionally. It will be able to monitor sites containing toxic chemical spills, leaking underground storage tanks and chemical waste dumps, potentially saving millions of dollars a year in the process.”
The sensor array contains a collection of different chemical resistors to detect a range of volatile organic compounds (VOCs). To make the resistors, Hughes first mixed commercial polymers that had been dissolved in a solvent with conductive carbon particles. He then painted this ink-like mixture onto electrodes in specially designed microfabricated circuits. If VOCs are present, the polymers absorb the compounds and swell, which in turn changes the electrical resistance in the circuit. The swelling and resistance change correspond to the concentration of the VOC. Once the chemical is removed, the polymers shrink back to normal. “By using four different kinds of polymers-one for each sensor-we think we can detect all solvents of interest,” Hughes says.
Ho and other team members devised the weatherproof packaging for the chemiresistor chip-without which the device could not be placed in water or underground. “The package is modular, like a watertight flashlight, and is fitted with O-rings,” Ho explains. “It can be unscrewed, allowing for easy exchange of components.” All told, the casing, constructed of stainless steel, measures a mere three centimeters in diameter. Chemical vapors pass through the casing to the chemiresistor array through a small window covered with a waterproof Gore-Tex membrane. When the device is placed in water, VOCs will partition across the membrane into the gas phase. The scientists recently placed the sensor at Sandia's Chemical Waste Landfill to see how well the device works outside the lab. There it is suspended about 60 feet down a screened well and logs data every hour. This field test will last for several weeks or months, and others are planned at Edwards Air Force Base and the Nevada Test Site. From the experiments, Ho, Hughes and their colleagues hope to determine the sensor's life span, as well as its performance when temperature, pressure and humidity vary.
“Over the next few years I expect we will see this invention being applied to DOE sites that require monitoring, remediation and/or long-term stewardship of contaminated sites, which currently spend millions of dollars for off-site analysis of manual samples,” Ho adds. “This device can also be applied to numerous commercial sites and applications, such as gas stations, which include more than two million underground storage tanks that require monitoring to satisfy the EPA requirements.”
And the electronic sniffer may offer at least part of the solution toward safeguarding the national water infrastructure by lowering the cost of such security tremendously. “A low security level might mean hiring a security guard and installing some detection features around critical assets, and that won't cost a lot,” Danneels says. “But to stop a fairly organized group from committing a terrorist act could be extremely expensive.”
Questions 31-35
Read the following statements and indicate how they reflect the information in the reading passage, by writing:
T if the statement is true
F if it is false, or
NC if it is not clear from the passage.
Write your answers in boxes 31_35 on your answer sheet.
Example Answer
Americans are confident about airport security F
31. September 11 made the Department of Energy worry about water supply security.
32 Sandia's water security system is environmentally friendly.
33. The U.S.'s major water distribution systems are basically identical.
34. Danneel's three basic steps apply to all U.S. water distribution systems.
Questions 36_40
36. Sandia's new monitoring system differs from traditional methods because it tests...
Write NO MORE THAN THREE WORDS as your answer in box 36 on your answer sheet.
37_38
What two reactions in the chemical resistors show the presence of VOCs?
Write NO MORE THAN TWO WORDS for each answer in boxes 37_38 on your answer sheet.
39. Besides the sensor's sensitivity to changes in surrounding factors, what else is the field test designed to find out?
Write TWO WORDS as your answer in box 39 on your answer sheet.
40. According to the passage, how will the electronic sniffer contribute to stopping terrorists contaminating the water supply?
Write NO MORE THAN FOUR WORDS as your answer in box 40 on your answer sheet.
Answer Key
Tips and Hints to Help You Raise Your Score
PASSAGE ONE
1. C
2. A
3. C
4. B
5. B
6. Benchmarking
7. (a range of ) service delivery
8. (performance) measures
9. productivity
10. Take Charge/ "Take Charge"
11. Feedback
12. Employee(s)/ staff
13. 30 days
PASSAGE TWO
1. C
2. D
3. B
PASSAGE THREE
1. iv
2. vii
3. viii
4. iii
5. ii
6. i
7. x
8. B
9. B
10. E
11. A
12. B
13. D
14. E
PASSAGE FOUR
1. NO
2. YES
3. YES
4. NOT GIVEN
PASSAGE FIVE
1. rigs and /or tanks
2. fish stocks
3. physical obstacles
4. concrete
5. commercial
PASSAGE SIX
1. D
2. C
3. F
4. G
TEST 1
READING PASSAGE ONE:
Question Answer Location of Answer in Text
1Cdiscovered in 1535 by Tomas de Berlanga...
2A"In that little world within itself."
3B"a successful example of cooperation."
4D"This will have the dual benefit."
5Eas a World Heritage Site by Unesco...
6A...his monumental work on evolution...
7B...environmental impact...team...Sanchez
Question Answer
897%
914
101,000 km
11B
12D
READING PASSAGE TWO：
Questions 13-19
Question Answer Location of Answer in Text
13hormones"...needs some cholesterol to make hormones and Vitamin D."
14vitamin D
15arteries"Excess cholesterol builds up in the arteries...
16heart"...increasing the danger of heart disease."
17HGM"By slowing down the function of the HMG enzyme..."
18draw on"...force the body to draw on the cholesterol "
19shortfall"...to make up the shortfall in its needs."
Questions 20-23
Question Answer Location of Answer in Text
20B"Doctors are...wondering if statins..."
21FParagraph 3
22E"...the same active ingredient found in statins."
23H"...undergo periodic blood tests..."
* The skills tested in 20-23 (matching phrases)are: skimming/scanning for detail; understanding paraphrase and gist; and making inferences.
Questions 24-27
24. NO
25. YES
26. NOT GIVEN
27. NO
READING PASSAGE THREE:
Questions 28-37
28. ix
29. vii
30. i
31. viii
32. vi
33. NOT GIVEN
34. YES
35. YES
36. NO
37. NOT GIVEN
Questions 38-41
Question Answer Location of Answer in Text
38A"Altruism doesn't come cheap."
39C"...the conditions were spartan;"
40H"...want short_term, meaningful vacations."
41F"...tide of growing disillusionment."
TEST 2
READING PASSAGE ONE:
Questions 1-5
Question Answer Location of Answer in Text
1E"...‘Ramsar sites' all over the world.
"
2A"...preserving the trackways..."
3B"...on an almost industrial scale..."
4C"...ritual sacrifice?"
5A"...a sprinkler system..."
Questions 6-11
6. NG
7. F
8. T
9. F
10. F
11. T
Questions 12-14
12. digging for peat/digging peat
13. Iron Age sites
14. radiocarbon dating
READING PASSAGE TWO:
Questions 15-17
Question Answer Location of Answer in Text
15B"clues that there was water"
16D"...located near the poles..."
17C"encourage Congress...green light"
Questions 18-20
Question Answer Location of Answer in Text
18three years"since it was launched in 1998."
19Ultraviolet lightparagraph 5
20Network of platesparagraph 7
Questions 21-28
Question Answer Location of Answer in Text
21O"there may have been oceans..."
22VW"...on the sunny sides of hills... evaporate almost instantly"
23LW"simply can't exist there."
24T"In our future work"
25V"...grew much higher"
26LW"...water would be associated..."
27Sparagraph 5
28T"...terraces and seismic”
READING PASSAGE THREE:
Questions 29-35
Question Answer Location of Answer in Text
29four eye diseases"...with the aim of..."
30Sightreach Prevention"...a program called..."
31Vitamin A"...key parts...Vitamin A."
32Bolivia"...in Bolivia soon."
33Sightreach Surgical"... through Sightreach Surgical."
34"childhood blindness""...focussing on ‘childhood blindness.’"
35five countries"...data...in five countries."
Questions 36-39
36. C
37. B
38. A
39. A
Questions 40-42
40. C & H
41. J & G
42. B & K
TEST 3
READING PASSAGE ONE:
Questions 1-5
Question Answer Focus of Paragraph
1vPrinciples of hypnosis that scientists agree upon.
2viiWhat the hypnotized subject feels and says
3iEffect of hypnotic suggestion on the brain.
4ixThe "memory" controversy.
5ivThe use of hypnotism as a healing technique.
Questions 6-8
6. *"2
7. *"5
8. *"6
Question 9-10
9. NO
10. NO
11. NOT GIVEN
12. YES
13. NOT GIVEN
READING PASSAGE TWO:
Questions 14-23
14. F
15. G
16. D
17. C
18. A
19. B
20. T
21. M
22. G
23. T
Questions 24-27
Question Answer Location of Answer in Text
24show initiative"the initiative to come from Africa."
25debt repayment"debt repayment...doomed to failure."
26(the) AIDS (epidemic)"AIDS...disastrous...life expectancy."
27"concerted action" Paragraph G
READING PASSAGE THREE:
Questions 28-31
28. NO
29. NOT GIVEN
30. YES
31. YES
Questions 32-35
Question Answer Focus of Paragraph
32v"Central to...is education."
33i"Human relationships must be."
34vi"The most reliable...family."
35iv"...make sure...securely attached."
Questions 36-39
36. (economically) strangled
37. endowment
38. benchmarks
39. C
TEST 4
READING PASSAGE ONE:
Question 1
Positive/Relatively minor (in any order)
Questions 2-4
2. *"benefits
3. *"pacify/block (in any order)
4. *"outweighs
Questions 5-8
5. *"NO
6. *"NOT GIVEN
7. *"YES
8. *"NO
Questions 9-10
9. *"motivation
10. remembering/picturing (them)
READING PASSAGE TWO:
Questions 11-13
Monacan Tribal Council/Sharon Long/Virginia
Humanities Foundation (in any order)
Questions 14-18
14. C
15. A
16. D
17. B
18. E
Questions 19-21
19. E
20. F
21. D
Question 22Answer: B
Question 23Answer: D
Question 24Answer: D
Question 25Answer: A
READING PASSAGE THREE:
Questions 26-32
Question Answer Location of Answer in Text
26YESLast sentence
27NO"...have a history as old as..."
28NO"...very difficult... to give up their cars."
29YES"...impossible to tell..."
30NOT GIVEN"Every major auto maker..."
31NO
32NOT GIVEN
Questions 33-34
33. C
34. B
Question 35
Inexpensive fuel/minimal maintenance/longer-living motor
(in any order)
Questions 36-38
36. sustainable option
37. common denominator
38. automotive giants
TEST 5
Reading Passage 1, Questions 1-14
1. *"B
2. *"C
3. *"A
4. *"C
5. *"A
6. *"negative impact
7. *"sleepiness
8. *"sleep_related
9. *"detriment
10. ix
11. iii
12. vii
13. i
14. iv
Reading Passage 2, Questions 15-28
15. 2025
16. prosperous countries
17. water refugees
18. 1900-1995
19. YES
20. NG
21. NO
22. YES
23. NO
24. B
25. D
26. C
27. B
28. A
Reading Passage 3, Questions 29-40
29. MIT
30. GT
31. IP
32. MIT
33. AT
34. GT
35. MIT
36. T
37. F
38. NG
39. T
40. F
TEST 6
1. C
2. B
3. C
4. A
5. A
6. cameras
7. on_board computer
8. upper deck
9. wheelchair section
10. computer_steered
11. tracks
12. boarding*
13. alighting*
* in either order
14. ii
15. v
16. vii
17. viii
18. iv
19. (regional) central banks
20. encourage growth
21. China
22. a decade ago
23. NO ("...slower but still positive growth...")
24. YES ("...because...pegged exchange rates.")
