如缺失，重度楔状缺损，Ⅱ度松动。x线片显示：根尖病变，牙周膜增宽，牙槽骨吸收1／2

如果要保留，治疗方案是

A:根管治疗并修复，然后可摘局部义齿修复缺失牙 B:经根管治疗、牙周治疗并修复，然后可摘局部义齿修复缺失牙 C:经牙周治疗后，然后可摘局部义齿修复缺失牙 D:可摘局部义齿修复缺失牙后，根管治疗并修复 E:可摘局部义齿修复缺失牙后，根管治疗、牙周治疗并修复

{{B}}第二篇{{/B}}

A:it is not easy to persuade manufacturers to adopt the new design. B:the team of engineers has not found any countermeasures. C:children like to ride bicycles at a very low speed. D:a lot of children were killed in bicycle accidents in the past 30 years.

Pushbike Peril
Low speed bicycle crashes can badly injure — or even kill — children if they fall onto the ends of the handlebars. So a team of engineers is redesigning the humble handlebar in a bid to make it safer.
Kristy Arbogast, a bioengineer at the Children’s Hospital of Philadelphia in Pennsylvania, began the project with her colleagues after a study of serious abdominal injuries in children in the past 30 years showed that more than a third were caused by bicycle accidents. "The task was to identify how the injuries occurred and come up with some countermeasures," she says.
By interviewing the children and their parents, Arbogast and her team were able tog reconstruct many of the accidents and identified a common mechanism responsible for serious injuries. They discovered that most occur when children hit an obstacle at a slow speed, causing them to topple over5. To maintain their balance they turn the handlebars through 90 degrees — but their momentum forces them into the end of the handlebars. The bike then falls over and the other end of the handlebars hits the ground, ramming it into their abdomen6.
The solution the group came up with is a handgrip fitted with a spring and damping system. The spring absorbs up to 50 per cent of the forces transmitted through the handlebars in an impact. The group hopes to commercialize the device, which should add only a few dollars to the cost of a bike. "But our task has been one of education because up until now, bicycle manufacturers were unaware of the problem," says Arbogast.
The team has also approached the US Consumer Product Safety Commission to try to persuade manufacturers to adopt the new design. A decision is expected later this year.

A:it is not easy to persuade manufacturers to adopt the new design. B:the team of engineers has not found any countermeasures. C:children like to ride bicycles at a very low speed. D:a lot of children were killed in bicycle accidents in the past 30 years.

{{B}}第二篇{{/B}}

A:it is not easy to persuade manufacturers to adopt the new design. B:the team of engineers has not found any countermeasures. C:children like to ride bicycles at a very low speed. D:a lot of children were killed in bicycle accidents in the past 30 years.

{{B}}第二篇{{/B}}

A:at 37.1 years. B:at 40 years. C:at 39.2 years. D:at 52 years.

{{B}}第三篇{{/B}}

A:it is not easy to persuade manufacturers to adopt the new design. B:the team of engineers has not found any countermeasures. C:children like to ride bicycles at a very low speed. D:a lot of children were killed in bicycle accidents in the past 30 years.

第二篇 Forty May Be the New 30 As Scientists Redefine Age 　　Is 40 really the new 30? In many ways people today act younger than their parents did at the same age. 　　Scientists have defined a new age concept and believe it could explain why populations are aging, but at the same time seem to be getting younger. 　　Instead of measuring aging by how long people have lived, the scientists have factored in how many more years people can probably still look forward to. 　　"Using that measure, the average person can get younger in the sense that he or she can have even more years to live as time goes on," said Warren Sanderson of the University of New York in Stony Brook. 　　He and Sergei Scherbov of the Vienna lnstitute of Demography （人口统计学） at the Austrian （奥地利的） Academy of Sciences， have used their method to estimate how the proportion of elderly people in Germany， Japan and the United States will change in the future. 　　The average German was 39.9 years old in 2000 and could plan to live for another 39.2 years, according to research reported in the journal Nature on Wednesday. 　　However, by 2050 the average German will be 51.9 years old and will be expected to live another 37.1 years. So middle age in 2050 would occur at around 52 years instead of 40 years as in 2000. 　　"As people have more and more years to live they have to save more and plan more and they effectively are behaving as if they were younger," said Sanderson. 　　Five years ago, the average American was 35.3 years old and could plan for 43.5 more years of life. By 2050, the researchers estimate it will increase to 41.7 years and 45.8 future years. 　　"A lot of our ski/Is, our education, our savings and the way we dear with our health care depend a great deal on how many years we have to live," said Sanderson. 　　This dimension of how many years people have to live has been completely ignored in the discussion of aging so far. In 2000, middle age for the average German occurred

A:at 37.1 years. B:at 40 years. C:at 39.2 years. D:at 52 years.

第二篇 Forty May Be the New 30 as Scientists Redefine Age Is 40 really the new 30?In many ways people today act younger than their parents did at the same age. Scientists have defined a new age concept and believe it could explain why populations are aging, but at the same time seem to be getting younger. Instead of measuring aging by how long people have lived, the scientists have factored in how many more years people can probably still look forward to. Using that measure, the average person can get younger in the sense that he or she can have even more years to live as time goes on, said Warren Sanderson of the University of New York in Stony Brook. He and Sergei Scherbov of the Vienna Institute of Demography at the Austrian Academy of Sciences, have used their method to estimate how the proportion of elderly people in Germany, Japan and the United States will change in the future. The average German was 39.9 years old in 2000 and could plan to live for another 39.2 years, according to research reported in the journal Nature on Wednesday. However, by 2050 the average German will be 51.9 years old and will be expected to live another 37.1 years. So middle age in 2050 would occur at around 52 years instead of 40 years as in 2000. As people have more and more years to live they have to save more and plan more and they effectively are behaving as if they were younger, said Sanderson. Five years ago, the average American was 35.3 years old and could plan for 43.5 more years of life. By 2050, the researchers estimate it will increase to 41.7 years and 45.8 future years. A lot of our skills, our education， our savings and the way we deal with our health care depend a great deal on how many years we have to live, said Sanderson. This dimension of how many years we have to live has been completely ignored in the discussion of aging so far. The new age concept takes into account the factor of

A:"future years. " B:"average years. " C:"past years. " D:"school years. "

第二篇 Forty May Be the New 30 as Scientists Redefine Age Is 40 really the new 30?In many ways people today act younger than their parents did at the same age. Scientists have defined a new age concept and believe it could explain why populations are aging, but at the same time seem to be getting younger. Instead of measuring aging by how long people have lived, the scientists have factored in how many more years people can probably still look forward to. Using that measure, the average person can get younger in the sense that he or she can have even more years to live as time goes on, said Warren Sanderson of the University of New York in Stony Brook. He and Sergei Scherbov of the Vienna Institute of Demography at the Austrian Academy of Sciences, have used their method to estimate how the proportion of elderly people in Germany, Japan and the United States will change in the future. The average German was 39.9 years old in 2000 and could plan to live for another 39.2 years, according to research reported in the journal Nature on Wednesday. However, by 2050 the average German will be 51.9 years old and will be expected to live another 37.1 years. So middle age in 2050 would occur at around 52 years instead of 40 years as in 2000. As people have more and more years to live they have to save more and plan more and they effectively are behaving as if they were younger, said Sanderson. Five years ago, the average American was 35.3 years old and could plan for 43.5 more years of life. By 2050, the researchers estimate it will increase to 41.7 years and 45.8 future years. A lot of our skills, our education， our savings and the way we deal with our health care depend a great deal on how many years we have to live, said Sanderson. This dimension of how many years we have to live has been completely ignored in the discussion of aging so far. In 2000, middle age for the average German occurred

A:at 37.1 years. B:at 40 years. C:at 39.2 years. D:at 52 years.

{{B}}第二篇{{/B}}

A:it is not easy to persuade manufacturers to adopt the new design. B:the team of engineers has not found any countermeasures. C:children like to ride bicycles at a very low speed. D:a lot of children were killed in bicycle accidents in the past 30 years.