About four billion people, or two-thirds of the world’s population, face severe water shortages during at least one month every year, far more than was previously thought, according to Arjen Y. Hoekstra, a professor of water management at the University of Twente in the Netherlands.In a paper published in the journal Science Advances, Dr. Hoekstra and his colleague Mesfin M. Mekonnen designed a computer model to create what they say is a more accurate picture of water scarcity around the world. Severe water scarcity can lead to crop failure and low crop yields, which could cause food price increases as well as famine and widespread starvation.An area experiences severe water shortage when its farms, industries and households consume double the amount of water available in that area.“That means that groundwater levels are falling, lakes are drying up, less water is flowing in rivers, and water supplies for industry and farmers are threatened,” Dr. Hoekstra said in an email.Not everyone would suffer equally. In more affluent countries, severe water scarcity could mean water rations (定量配给) for showering and gardening, while in very poor countries it could lead to shortages of drinking water.Previous studies had estimated that between 1.7 and 3.1 billion people were affected by extreme water shortages. But according to Dr. Hoekstra, those studies either used measurements that were too general in size or used yearly averages that were not as precise as monthly data.“Freshwater scarcity is a major risk to the global economy, affecting four billion people directly,” Dr. Hoekstra said. “But since the remaining people in the world receive part of their food from the affected areas, it involves us all.”1. What does Dr. Hoekstra find in his research?A) About four billion people suffer severe water shortage every day.B) Computer models are more accurate in tracking water shortage.C) Water shortages were far more than was previously thought. D) Severe water shortage could lead to widespread starvation.2. What does severe water shortage mean according to Dr. Hoekstra?A) It means farms and industries cannot operate normally.B) It means household water supplies are threatened.C) It means that the groundwater levels are falling. D) It means that rivers have been dried up.3. How do water shortages affect wealthier countries?A) There will be a lack of supply in drinking water.B) There will be a fixed amount of water for showering. C) There will be harsh penalties for gardening.D) There will be a decrease in biodiversity.4. What does Dr. Hoekstra say about the previous studies on water shortage?A) The monthly averages they used are not precise.B) The measurements they used are too general in size. C) The estimates they made fail to consider freshwater scarcity.D) The number of people affected by water shortage is not accurate.5. Why does Dr. Hoekstra say the water issue in most affected areas involves us all?A) Because each of us is an integral part of the global ecosystem.B) Because the rest of us receive part of our food from these areas. C) Because the situation in these areas is rather critical and serious.D) Because the global economy has linked all countries and people.

About four billion people, or two-thirds of the world’s population, face severe water shortages during at least one month every year, far more than was previously thought, according to Arjen Y. Hoekstra, a professor of water management at the University of Twente in the Netherlands. In a paper published in the journal Science Advances, Dr. Hoekstra and his colleague Mesfin M. Mekonnen designed a computer model to create what they say is a more accurate picture of water scarcity around the world. Severe water scarcity can lead to crop failure and low crop yields, which could cause food price increases as well as famine and widespread starvation. An area experiences severe water shortage when its farms, industries and households consume double the amount of water available in that area. “That means that groundwater levels are falling, lakes are drying up, less water is flowing in rivers, and water supplies for industry and farmers are threatened,” Dr. Hoekstra said in an email. Not everyone would suffer equally. In more affluent countries, severe water scarcity could mean water rations (定量配给) for showering and gardening, while in very poor countries it could lead to shortages of drinking water. Previous studies had estimated that between 1.7 and 3.1 billion people were affected by extreme water shortages. But according to Dr. Hoekstra, those studies either used measurements that were too general in size or used yearly averages that were not as precise as monthly data. “Freshwater scarcity is a major risk to the global economy, affecting four billion people directly,” Dr. Hoekstra said. “But since the remaining people in the world receive part of their food from the affected areas, it involves us all.”1. What does Dr. Hoekstra find in his research?A)  About four billion people suffer severe water shortage every day.B)  Computer models are more accurate in tracking water shortage.C)  Water shortages were far more than was previously thought. D)  Severe water shortage could lead to widespread starvation.2. What does severe water shortage mean according to Dr. Hoekstra?A)  It means farms and industries cannot operate normally.B)  It means household water supplies are threatened.C)  It means that the groundwater levels are falling. D)  It means that rivers have been dried up.3. How do water shortages affect wealthier countries?A)  There will be a lack of supply in drinking water.B)  There will be a fixed amount of water for showering. C)  There will be harsh penalties for gardening.D)  There will be a decrease in biodiversity.4. What does Dr. Hoekstra say about the previous studies on water shortage?A)  The monthly averages they used are not precise.B)  The measurements they used are too general in size. C)  The estimates they made fail to consider freshwater scarcity.D)  The number of people affected by water shortage is not accurate.5. Why does Dr. Hoekstra say the water issue in most affected areas involves us all?A)  Because each of us is an integral part of the global ecosystem.B)  Because the rest of us receive part of our food from these areas. C)  Because the situation in these areas is rather critical and serious.D)  Because the global economy has linked all countries and people.