Scientists in the United States say plant life has increased on Earth in the past twenty years and that in every area of plant growth the increase is the result of weather conditions.

         Eight scientists from across the United States did the study. The space agency NASA and the Department of Energy paid for it. The findings were published in the magazine Science.

         The researchers spent one and a half years examining weather satellite information. The information was recorded from 1982 to 1999. That period was one of the warmest on record. Researchers found that rainfall generally increased during that time.

         The satellites measured the number of leaves on plants and the amount of sunlight taken in. The scientists used that information to estimate what is called net primary production. This is total amount of carbon stored in land plants.

         The scientists report a 6% increase in stored carbon since 1982. They say gains were high in equatorial areas, especially around the Amazon River in South America. The area alone had a 1% increase in the net primary production.

Ramakrishna Nemani of the University of Montana in Missoula headed the study. He says reduced cloud cover led to growth in Amazon area. He also says the lack of clouds allowed more sunlight to get through. More sunlight meant increases in photosynthesis(光合作用). That is the process by which plants use energy from sunlight to produce the chemicals they need to grow.

         Northern Canada, the north-central United States and northern Europe were second in increased plant growth. Ramakrishna Nemani says a rise in temperature helped plants there.

         All together, the report says 25% of areas of plant life on Earth experienced increases. But the scientists also note increase in the number of people on Earth and carbon dioxide levels in the atmosphere. Ranga Myneni of Boston University in Massachusetts, another study scientist says humans use about half the net primary production on Earth. And he notes that the world population grew by 36% during the period of time studied.

1.Which of the following is in charge of the study?

         A. The space agency NASA of the US.

         B. The Department of Energy of the US.

         C. Ramakrishna Nemani in Missoula.

         D. Ranga Myneni in Massachusetts.

2.What’s the main cause of the plant growth put forward by the study?

         A. Growth in population.

         B. Regional features.

         C. Seasonal variation.

         D. Weather conditions

3. Why do scientists believe that reduced cloud cover has led to the plant growth in           the Amazon area?

         A. Because plants could take in more sunlight.

         B. Because plants could get more rainfall.

         C. Because plants could enjoy cooler air.

         D. Because plants suffer less from natural disasters.

4. Which of the following descriptions about the years from 1982 to 1999 is TRUE?

         A. It was the warmest on record.

         B. Rainfall decreased little by little.

         C. World population grew by 25%.

         D. Stored carbon increased by 6%.

       Scientists in the United States say plant life has increased on Earth in the past twenty years and that in every area of plant growth the increase is the result of weather conditions.

       Eight scientists from across the United States did the study. The space agency NASA and the Department of Energy paid for it. The findings were published in the magazine Science.

       The researchers spent one and a half years examining weather satellite information. The information was recorded from 1982 to 1999. That period was one of the warmest on record. Researchers found that rainfall generally increased during that time.

       The satellites measured the number of leaves on plants and the amount of sunlight taken in. The scientists used that information to estimate what is called net primary production. This is total amount of carbon stored in land plants.

       The scientists report a 6% increase in stored carbon since 1982. They say gains were high in equatorial areas, especially around the Amazon River in South America. The area alone had a 1% increase in the net primary production.

Ramakrishna Nemani of the University of Montana in Missoula headed the study. He says reduced cloud cover led to growth in Amazon area. He also says the lack of clouds allowed more sunlight to get through. More sunlight meant increases in photosynthesis(光合作用). That is the process by which plants use energy from sunlight to produce the chemicals they need to grow.

       Northern Canada, the north-central United States and northern Europe were second in increased plant growth. Ramakrishna Nemani says a rise in temperature helped plants there.

       All together, the report says 25% of areas of plant life on Earth experienced increases. But the scientists also note increase in the number of people on Earth and carbon dioxide levels in the atmosphere. Ranga Myneni of Boston University in Massachusetts, another study scientist says humans use about half the net primary production on Earth. And he notes that the world population grew by 36% during the period of time studied.

Which of the following is in charge of the study?

       A. The space agency NASA of the US.

       B. The Department of Energy of the US.

       C. Ramakrishna Nemani in Missoula.

       D. Ranga Myneni in Massachusetts.

What’s the main cause of the plant growth put forward by the study?

       A. Growth in population.

       B. Regional features.

       C. Seasonal variation.

       D. Weather conditions

Why do scientists believe that reduced cloud cover has led to the plant growth in       the Amazon area?

       A. Because plants could take in more sunlight.

       B. Because plants could get more rainfall.

       C. Because plants could enjoy cooler air.

       D. Because plants suffer less from natural disasters.

Which of the following descriptions about the years from 1982 to 1999 is TRUE?

       A. It was the warmest on record.

       B. Rainfall decreased little by little.

       C. World population grew by 25%.

       D. Stored carbon increased by 6%.

       Scientists in the United States say plant life has increased on Earth in the past twenty years and that in every area of plant growth the increase is the result of weather conditions.

       Eight scientists from across the United States did the study．The space agency NASA and the Department of Energy paid for it．The findings were published in the magazine Science.

       The researchers spent one and a half years examining weather satellite information．The information was recorded from 1982 to 1999．That period was one of the warmest on record．Researchers found that rainfall generally increased during that time.

       The satellites measured the number of leaves on plants and the amount of sunlight taken in．The scientists used that information to estimate what is called net primary production．This is total amount of carbon stored in land plants.

       The scientists report a 6% increase in stored carbon since 1982．They say gains were high in equatorial areas, especially around the Amazon River in South America．The area alone had a 1% increase in the net primary production.

Ramakrishna Nemani of the University of Montana in Missoula headed the study．He says reduced cloud cover led to growth in Amazon area．He also says the lack of clouds allowed more sunlight to get through．More sunlight meant increases in photosynthesis（光合作用）．That is the process by which plants use energy from sunlight to produce the chemicals they need to grow.

       Northern Canada, the north-central United States and northern Europe were second in increased plant growth．Ramakrishna Nemani says a rise in temperature helped plants there.

       All together, the report says 25% of areas of plant life on Earth experienced increases．But the scientists also note increase in the number of people on Earth and carbon dioxide levels in the atmosphere．Ranga Myneni of Boston University in Massachusetts, another study scientist says humans use about half the net primary production on Earth．And he notes that the world population grew by 36% during the period of time studied.

1．Which of the following is in charge of the study?

       A．The space agency NASA of the US.       B．The Department of Energy of the US.

       C．Ramakrishna Nemani in Missoula.         D．Ranga Myneni in Massachusetts.

2．What’s the main cause of the plant growth put forward by the study?

       A．Growth in population.                          B．Regional features.

       C．Seasonal variation.                               D．Weather conditions

3．Why do scientists believe that reduced cloud cover has led to the plant growth in the Amazon area?

       A．Because plants could take in more sunlight.

       B．Because plants could get more rainfall.

       C．Because plants could enjoy cooler air.

       D．Because plants suffer less from natural disasters.

4．Which of the following descriptions about the years from 1982 to 1999 is TRUE?

       A．It was the warmest on record.

       B．Rainfall decreased little by little.

       C．World population grew by 25%.

       D．Stored carbon increased by 6%.

.
III. Reading Comprehension     
Section A
Directions: For each blank in the following passage there are four words or phrases marked A, B, C and D.  Fill in each blank with the word or phrase that best fits the context.
Your cell phone holds secrets about you. Besides the names and   50   that you’ve programmed into it, traces of your DNA remain on it, according to a new study.
　　DNA is genetic material that appears in every cell. Like your fingerprint, your DNA is unique to you   51   you have an identical twin. Scientists today routinely analyze DNA in blood, saliva (唾液), or hair   52   behind at the scene of a crime. The results often help detectives identify   53   and their victims. Your cell phone can   54   more about you than you might think.
　　Meghan J. McFadden, a scientist at McMaster University1in Hamilton, Ontario, heard about a crime in which the suspect（嫌疑犯）bled onto a cell phone and later dropped the   55  . This made her wonder whether traces of DNA remained on cell phones ___ even when no blood was involved.　    56   she and colleague Margaret Wallace of the City University of New York analyzed the flip-open phones(翻盖手机) of 10 volunteers. They used swabs(药签) to collect   57   traces of the users from two parts of the phone: the outside, where the user holds it, and the   58  , which is placed at the user’s ear.
The scientists scrubbed the phones using a solution made mostly of alcohol. The aim of washing was to   59   all detectable (可查明的) traces of DNA. The owners got their phones back for another week.   60   the researchers collected the phones and repeated the swabbing of each phone once more.
The scientists discovered DNA that   61   to the phone’s owner on each of the phones. Better samples were collected from the outside of each phone, but those swabs also   62    DNA of other people who had apparently also handled the phone.   63  , DNA showed up even in swabs that were taken immediately after the phones were scrubbed. That suggests that washing won’t remove all traces of evidence from a criminal’s device. So cell phones can now be added to the   64   of clues that can settle a crime-scene investigation.
50. A. secrets　                B. music                      C. numbers                  D. films
51. A. because                   B. unless                      C. although                  D. if
52. A. kept                        B. dropped                   C. stayed                      D. left
53. A. criminals                 B. clues                   C. witnesses                 D. policemen
54. A. reveal                     B. convince                  C. acquire                     D. value
55. A. document                 B. paper                             C. card                        D. device
56. A. However                 B. But                          C. So                          D. For
57. A. invisible                  B. non-existent             C. missing                   D. apparent
58. A. microphone           B. keys                        C. screen                     D. speaker
59. A. preserve                   B. revise                      C. remove                    D. protect
60.   A. Then                        B. Thus                       C. Meanwhile               D. Otherwise
61.   A. stuck                       B. belonged                 C. happened                 D. contributed
62. A. took in                    B. mixed with              C. picked up                D. gave out
63.   A. Generally                B. Shortly                    C. Disappointedly         D. Surprisingly
64. A. explanation              B. list                          C. book                       D. discovery