Logging is not banned chiefly because

A:scientists are overestimating the damage. B:people benefit economically from it. C:some creatures are only threatened but not endangered. D:it provides jobs to the consumers.

Studies of deforestation(采伐森林，毁坏森林) in Amazon rainforest have underestimated the actual extent of forest loss by half or more, according to a study published in the April 8, 1999, issue of the journal Nature.
Past efforts to estimate deforestation in the Amazon have relied on satellite images to calculate forest loss. The new analysis found that satellite images were useful for estimating deforestation by logging(伐木)and fires on an extent of land, but failed to capture numerous smaller pockets of damage, including damages caused by selective logging(a harvesting technique in which only selected trees are removed) and surface fires, which is often hard to detect from satellite images, as new growth quickly masks it.
The new study focused on Brazil’s Amazon region, where most of the rainforest is located. The researchers interviewed 1,500 wood mill operators and 200 landowners about logging practices, harvest records and fire damages on their lands. The researchers verified the information collected by measuring the actual wood harvest in selected parts of forest, and by surveying fire damages from an airplane at over 1,100 sample points.
The research team found that damage from the fires varied significantly from year to year due to larger environmental factors, but roughly similar damage caused by logging. They determined that actual deforestation in the Brazilian Amazon was at least double the damage estimates derived from satellite images.
Damages caused by logging and fires threatened the Amazon rainforest. Sunlight can penetrate holes in the forest shelter and reach the floor, drying plants and increasing the risk of fire. At the global level, many scientists worry that continued burning and logging in the forest will further raise levels of carbon dioxide in the atmosphere. Rising levels of carbon dioxide—a so-called greenhouse gas because it traps heat in the lower atmosphere— has been linked to global warming.
Strict limits on logging, stronger efforts preventing fire, and controls on development could all help slow deforestation, the researchers said.

Which of the following was NOT done by the researchers in their study（）

A:Interviewing wood mill operators and landowners about logging. B:Surveying fire damages from the airplane. C:Measuring the actual wood harvest in selected parts of forest. D:Surveying the damage of forest caused by Amazon floo

Studies of deforestation(采伐森林，毁坏森林) in Amazon rainforest have underestimated the actual extent of forest loss by half or more, according to a study published in the April 8, 1999, issue of the journal Nature.
Past efforts to estimate deforestation in the Amazon have relied on satellite images to calculate forest loss. The new analysis found that satellite images were useful for estimating deforestation by logging(伐木)and fires on an extent of land, but failed to capture numerous smaller pockets of damage, including damages caused by selective logging(a harvesting technique in which only selected trees are removed) and surface fires, which is often hard to detect from satellite images, as new growth quickly masks it.
The new study focused on Brazil’s Amazon region, where most of the rainforest is located. The researchers interviewed 1,500 wood mill operators and 200 landowners about logging practices, harvest records and fire damages on their lands. The researchers verified the information collected by measuring the actual wood harvest in selected parts of forest, and by surveying fire damages from an airplane at over 1,100 sample points.
The research team found that damage from the fires varied significantly from year to year due to larger environmental factors, but roughly similar damage caused by logging. They determined that actual deforestation in the Brazilian Amazon was at least double the damage estimates derived from satellite images.
Damages caused by logging and fires threatened the Amazon rainforest. Sunlight can penetrate holes in the forest shelter and reach the floor, drying plants and increasing the risk of fire. At the global level, many scientists worry that continued burning and logging in the forest will further raise levels of carbon dioxide in the atmosphere. Rising levels of carbon dioxide—a so-called greenhouse gas because it traps heat in the lower atmosphere— has been linked to global warming.
Strict limits on logging, stronger efforts preventing fire, and controls on development could all help slow deforestation, the researchers said.

What cannot be concluded about the satellite images（）

A:Satellite images are useless for calculating forest loss. B:Satellite images cannot detect forest loss by selective logging. C:Satellite images were not accurate because of changing environmental factors. D:Satellite images showed half or less of the actual deforestation in Brazilian Amazon.

Studies of deforestation(采伐森林，毁坏森林) in Amazon rainforest have underestimated the actual extent of forest loss by half or more, according to a study published in the April 8, 1999, issue of the journal Nature.
Past efforts to estimate deforestation in the Amazon have relied on satellite images to calculate forest loss. The new analysis found that satellite images were useful for estimating deforestation by logging(伐木)and fires on an extent of land, but failed to capture numerous smaller pockets of damage, including damages caused by selective logging(a harvesting technique in which only selected trees are removed) and surface fires, which is often hard to detect from satellite images, as new growth quickly masks it.
The new study focused on Brazil’s Amazon region, where most of the rainforest is located. The researchers interviewed 1,500 wood mill operators and 200 landowners about logging practices, harvest records and fire damages on their lands. The researchers verified the information collected by measuring the actual wood harvest in selected parts of forest, and by surveying fire damages from an airplane at over 1,100 sample points.
The research team found that damage from the fires varied significantly from year to year due to larger environmental factors, but roughly similar damage caused by logging. They determined that actual deforestation in the Brazilian Amazon was at least double the damage estimates derived from satellite images.
Damages caused by logging and fires threatened the Amazon rainforest. Sunlight can penetrate holes in the forest shelter and reach the floor, drying plants and increasing the risk of fire. At the global level, many scientists worry that continued burning and logging in the forest will further raise levels of carbon dioxide in the atmosphere. Rising levels of carbon dioxide—a so-called greenhouse gas because it traps heat in the lower atmosphere— has been linked to global warming.
Strict limits on logging, stronger efforts preventing fire, and controls on development could all help slow deforestation, the researchers said.

This passage mainly tells us（）

A:past efforts to estimate deforestation in the Amazon have completely failed B:that damages caused by logging and fires threaten the Amazon rain forest C:Amazon rainforest disappears faster than thought D:that satellite images are made use of for estimating deforestation

Studies of deforestation(采伐森林，毁坏森林) in Amazon rainforest have underestimated the actual extent of forest loss by half or more, according to a study published in the April 8, 1999, issue of the journal Nature.
Past efforts to estimate deforestation in the Amazon have relied on satellite images to calculate forest loss. The new analysis found that satellite images were useful for estimating deforestation by logging(伐木)and fires on an extent of land, but failed to capture numerous smaller pockets of damage, including damages caused by selective logging(a harvesting technique in which only selected trees are removed) and surface fires, which is often hard to detect from satellite images, as new growth quickly masks it.
The new study focused on Brazil’s Amazon region, where most of the rainforest is located. The researchers interviewed 1,500 wood mill operators and 200 landowners about logging practices, harvest records and fire damages on their lands. The researchers verified the information collected by measuring the actual wood harvest in selected parts of forest, and by surveying fire damages from an airplane at over 1,100 sample points.
The research team found that damage from the fires varied significantly from year to year due to larger environmental factors, but roughly similar damage caused by logging. They determined that actual deforestation in the Brazilian Amazon was at least double the damage estimates derived from satellite images.
Damages caused by logging and fires threatened the Amazon rainforest. Sunlight can penetrate holes in the forest shelter and reach the floor, drying plants and increasing the risk of fire. At the global level, many scientists worry that continued burning and logging in the forest will further raise levels of carbon dioxide in the atmosphere. Rising levels of carbon dioxide—a so-called greenhouse gas because it traps heat in the lower atmosphere— has been linked to global warming.
Strict limits on logging, stronger efforts preventing fire, and controls on development could all help slow deforestation, the researchers said.

Which of the following is NOT the reason for the greenhouse effect（）

A:Uncontrolled development. B:A warming atmosphere at a global level. C:Sunlight reaches the forest floor, dries plants and lights fires. D:No limits on logging and bad fire preventing efforts.

Studies of deforestation(采伐森林，毁坏森林) in Amazon rainforest have underestimated the actual extent of forest loss by half or more, according to a study published in the April 8, 1999, issue of the journal Nature.
Past efforts to estimate deforestation in the Amazon have relied on satellite images to calculate forest loss. The new analysis found that satellite images were useful for estimating deforestation by logging(伐木)and fires on an extent of land, but failed to capture numerous smaller pockets of damage, including damages caused by selective logging(a harvesting technique in which only selected trees are removed) and surface fires, which is often hard to detect from satellite images, as new growth quickly masks it.
The new study focused on Brazil’s Amazon region, where most of the rainforest is located. The researchers interviewed 1,500 wood mill operators and 200 landowners about logging practices, harvest records and fire damages on their lands. The researchers verified the information collected by measuring the actual wood harvest in selected parts of forest, and by surveying fire damages from an airplane at over 1,100 sample points.
The research team found that damage from the fires varied significantly from year to year due to larger environmental factors, but roughly similar damage caused by logging. They determined that actual deforestation in the Brazilian Amazon was at least double the damage estimates derived from satellite images.
Damages caused by logging and fires threatened the Amazon rainforest. Sunlight can penetrate holes in the forest shelter and reach the floor, drying plants and increasing the risk of fire. At the global level, many scientists worry that continued burning and logging in the forest will further raise levels of carbon dioxide in the atmosphere. Rising levels of carbon dioxide—a so-called greenhouse gas because it traps heat in the lower atmosphere— has been linked to global warming.
Strict limits on logging, stronger efforts preventing fire, and controls on development could all help slow deforestation, the researchers said.

Which of the following was NOT done by the researchers in their study（）

A:Interviewing wood mill operators and landowners about logging. B:Surveying fire damages from the airplane. C:Measuring the actual wood harvest in selected parts of forest. D:Surveying the damage of forest caused by Amazon floo

Rock Co. wants to purchase lumber from Logging Co.. Rock Co. and Logging Co. agree that a letter of credit will be used for payment. Who is the applicant（）

A:Rock Co B:Logging Co C:Bank D:None of them