Aging is not a disease, but as a person passes maturity, the cells of the body and the (39) they form do not function as well as they (40) in childhood and adolescence (青春期). The body provides less (41) against disease and is more prone (42) accident.A number of related cause may (43) aging. Some cells of the body have a fairly long life, but they are not (44) when they die. As a person ages, (45) of brain cells and muscle cells decrease, (46) body cells die and are replaced by new cells. In an aging person the (47) cells may not be as viable (能生存的) or as capable (48) growth as those of a young person.Another (49) in aging may be changes within the cells (50) . Some of the protein chemicals in cells are known (51) with age and become less elastic. This is why the skin of old people wrinkles and (52) . This is also the reason old people (53) in height. There may be other more important chemical changes in the cells. Some complex cell chemicals, such as RNA, store and (54) information that the cell need. Aging may affect this (55) and change the information carrying molecules so that they do not transmit the information as well.

53（　）

A:shorten  B:shrink  C:lengthen  D:decrease

Throughout history man has had to accept the fact that all living things must die, but people now live longer than they (36) . Yet, all living things still show the (37) of aging, which will eventually. (38) death.
Aging is not a disease, but as a person passes maturity, the cells of the body and the (39) they form do not function as well as they (40) in childhood and adolescence (青春期). The body provides less (41) against disease and is more prone (42) accident.
A number of related cause may (43) aging. Some cells of the body have a fairly long life, but they are not (44) when they die. As a person ages, (45) of brain cells and muscle cells decrease, (46) body cells die and are replaced by new cells. In an aging person the (47) cells may not be as viable (能生存的) or as capable (48) growth as those of a young person.
Another (49) in aging may be changes within the cells (50) . Some of the protein chemicals in cells are known (51) with age and become less elastic. This is why the skin of old people wrinkles and (52) . This is also the reason old people (53) in height. There may be other more important chemical changes in the cells. Some complex cell chemicals, such as RNA, store and (54) information that the cell need. Aging may affect this (55) and change the information carrying molecules so that they do not transmit the information as well.

39（）

A:shorten B:shrink C:lengthen D:decrease

Throughout history man has had to accept the fact that all living things must die, but people now live longer than they (36) . Yet, all living things still show the (37) of aging, which will eventually. (38) death.
Aging is not a disease, but as a person passes maturity, the cells of the body and the (39) they form do not function as well as they (40) in childhood and adolescence (青春期). The body provides less (41) against disease and is more prone (42) accident.
A number of related cause may (43) aging. Some cells of the body have a fairly long life, but they are not (44) when they die. As a person ages, (45) of brain cells and muscle cells decrease, (46) body cells die and are replaced by new cells. In an aging person the (47) cells may not be as viable (能生存的) or as capable (48) growth as those of a young person.
Another (49) in aging may be changes within the cells (50) . Some of the protein chemicals in cells are known (51) with age and become less elastic. This is why the skin of old people wrinkles and (52) . This is also the reason old people (53) in height. There may be other more important chemical changes in the cells. Some complex cell chemicals, such as RNA, store and (54) information that the cell need. Aging may affect this (55) and change the information carrying molecules so that they do not transmit the information as well.

38（）

A:shorten B:shrink C:lengthen D:decrease

Prolonging Human Life
Prolonging human life has increased the size of the human population. Many people alive today would have died of childhood diseases if they had been born 100 years ago. Because more people live longer, there are more people around at any given time. In fact, it is a decrease in death rates, not an increase in birthrates, that has led to the population explosion.
Prolonging human life has also increased the dependency load. In all societies, people who are disabled or too young or too old to work are dependent on the rest of society to provide for them. In hunting and gathering cultures, old people who could not keep up might be left behind to die. In times of famine, infants might be allowed to die because they could not survive if their parents starved, whereas if the parents survived they could have another child. In most contemporary societies, people feel a moral obligation to keep people alive whether they can work or not. We have a great many people today who live past the age at which they want to work or are able to work; we also have roles which require people to retire at a certain age. Unless these people were able to save money for their retirement, somebody else must support them. In the United States many retired people live on social security checks which are so little that they must live in near poverty. Older people have more illness than young or middle-aged people; unless they have wealth or private or government insurance, they must often "go on welfare” if they have a serious illness.
When older people become senile or too weak and ill to care for themselves, they create grave problems for their families. In the past and in some traditional cultures, they would be cared for at home until they died. Today, with must members of a household working or in school, there is often no one at home who can care for a sick or weak person. To meet this need, a great many nursing homes and convalescent hospitals have been built. These are often profit-making organizations, although some are sponsored by religious and other nonprofit groups. While a few of these institutions are good, most of them are simply "dumping grounds" for the dying in which "care" is given by poorly paid, overworked, and underskilled personnel.

The writer believes that the population explosion results from（　）

A:an increase in birthrates. B:the industrial development. C:a decrease in death rates. D:cultural advances.

The grid computing is a new （） technology connecting the distributed and （） resources to the high-speed network and integrating a super-computer of processing capacity. The significance and architecture of the grid computing is explained. Several kernel technology such as OGSI, resource management, task management, task scheduling, high rate communication and security are described. Aiming at the particularity of the grid computing environment a mechanism similar to the technology of the search engine is designed to registry, discovery and （） the resources in the grid. The whole model of the resource management is built by connecting task manager in the local resource management system to others with P2P model. The task may migrate among the task managers in order to （） the load. The task users summit may be executed in relatively tight resource set, which will not only decrease the total communication overheads of the whole task but also （） the performance of the system.

The task may migrate among the task managers in order to （） the load.

A:decrease B:balance C:enhance D:keep

The grid computing is a new （） technology connecting the distributed and （） resources to the high-speed network and integrating a super-computer of processing capacity. The significance and architecture of the grid computing is explained. Several kernel technology such as OGSI, resource management, task management, task scheduling, high rate communication and security are described. Aiming at the particularity of the grid computing environment a mechanism similar to the technology of the search engine is designed to registry, discovery and （） the resources in the grid. The whole model of the resource management is built by connecting task manager in the local resource management system to others with P2P model. The task may migrate among the task managers in order to （） the load. The task users summit may be executed in relatively tight resource set, which will not only decrease the total communication overheads of the whole task but also （） the performance of the system.

which will not only decrease the total communication overheads of the whole task but also （） the performance of the system.

A:decrease B:enhance C:keep D:balance

The grid computing is a new (66) technology connecting the distributed and (67) resources to the high-speed network and integrating a super-computer of processing capacity. The significance and architecture of the grid computing is explained. Several kernel technology such as OGSI, resource management, task management, task scheduling, high rate communication and security are described. Aiming at the particularity of the grid computing environment a mechanism similar to the technology of the search engine is designed to registry, discovery and (68) the resources in the grid. The whole model of the resource management is built by connecting task manager in the local resource management system to others with P2P model. The task may migrate among the task managers in order to (69) the load. The task users summit may be executed in relatively tight resource set, which will not only decrease the total communication overheads of the whole task but also (70) the performance of the system.

（69）是（）

A:decrease B:balance C:enhance D:keep

The grid computing is a new (66) technology connecting the distributed and (67) resources to the high-speed network and integrating a super-computer of processing capacity. The significance and architecture of the grid computing is explained. Several kernel technology such as OGSI, resource management, task management, task scheduling, high rate communication and security are described. Aiming at the particularity of the grid computing environment a mechanism similar to the technology of the search engine is designed to registry, discovery and (68) the resources in the grid. The whole model of the resource management is built by connecting task manager in the local resource management system to others with P2P model. The task may migrate among the task managers in order to (69) the load. The task users summit may be executed in relatively tight resource set, which will not only decrease the total communication overheads of the whole task but also (70) the performance of the system.

（70）是（）

A:decrease B:enhance C:keep D:balance

The grid computing is a new (66) technology connecting the distributed and (67) resources to the high-speed network and integrating a super-computer of processing capacity. The significance and architecture of the grid computing is explained. Several kernel technology such as OGSI, resource management, task management, task scheduling, high rate communication and security are described. Aiming at the particularity of the grid computing environment a mechanism similar to the technology of the search engine is designed to registry, discovery and (68) the resources in the grid. The whole model of the resource management is built by connecting task manager in the local resource management system to others with P2P model. The task may migrate among the task managers in order to (69) the load. The task users summit may be executed in relatively tight resource set, which will not only decrease the total communication overheads of the whole task but also (70) the performance of the system.

（69）处填（）。

A:decrease B:balance C:enhance D:keep

The grid computing is a new (66) technology connecting the distributed and (67) resources to the high-speed network and integrating a super-computer of processing capacity. The significance and architecture of the grid computing is explained. Several kernel technology such as OGSI, resource management, task management, task scheduling, high rate communication and security are described. Aiming at the particularity of the grid computing environment a mechanism similar to the technology of the search engine is designed to registry, discovery and (68) the resources in the grid. The whole model of the resource management is built by connecting task manager in the local resource management system to others with P2P model. The task may migrate among the task managers in order to (69) the load. The task users summit may be executed in relatively tight resource set, which will not only decrease the total communication overheads of the whole task but also (70) the performance of the system.

（70）处填（）。

A:decrease B:enhance C:keep D:balance