No one knows exactly how many disabled people there are in the world, but estimates suggest the figure is over 450 million. The number of disabled people in India alone is probably more than double the total population of Canada.
In the United Kingdom, about one in ten people have some disability. Disability is not just something that happens to other people: as get older, many of us will become less mobile, hard of hearing or have failing eyesight.
Disablement can take many forms and occur at any time of life. Some people are born with disabilities. Many others become disabled as they get older. There are many progressive disabling diseases. The longer time goes on, the worse they become. Some people are disabled in accidents. Many others may have a period of disability in the form of a mental illness. All are affected by people’s attitude towards them.
Disabled people face many physical barriers. Next time you go shopping or to work or visit friends, imagine how you would manage if you could not get up steps, or on to buses and trains. How would you cope if you could not see where you were going or could not hear the traffic But there are other barriers: prejudice can be even harder to break down and ignorance inevitably represents by far the greatest barrier of all. It is almost impossible for the able-bodied to fully appreciate what the severely disabled go through, so it is important to draw attention to these barriers and sow that it is the individual person and their ability, not their disability, which counts.

The last word of the passage "counts" most probably means" () ".

A team at the California-based Salk Institute, one of the world’s leading research centers on biological sciences, has created a special new breed of HIV and has started negotiations with the US Food and Drug Administration (FDA) to begin clinical gene therapy (治疗) trials this year. The first trials are expected to involve patients suffering from cancers that cannot be cured by surgery although project leader Professor Inder Verma said the HIV technique would have "far wider applications".
The plan remains very likely to cause controversy since it involves making use of a virus which has caused more than 22 million deaths around the world in the past two decades. Verma said that the idea of using HIV for a beneficial purpose was "shocking" but the fierce nature of HIV had disappeared by having all six of the potentially deadly genes removed.
Illnesses such as various cancers are caused when a gene in a patient’s body fails to work properly. In the past two years, breakthroughs in genetics (遗传学) have led gene therapy scientists to try and replace the genes that do not function normally.
Unfortunately, the body’s immune defenses have been known to attack the modified genes and make them lose their effects before they can start their task and progress in the field has been held up by the lack of a suitable carrier.
The HIV virus has the ability to escape from, and then destroy, the immune defense ceils designed to protect our bodies and this makes it attractive to scientists as a way of secretly conveying replacement genes into patients’ bodies.

A.overtaken
B.overseen
C.overlooked
D.overwhelmed