In the Caucasus region of Russia, nearly 50 out of every 100,000 people live to celebrate their 100th birthday, and many don’t stop at 100! By comparison, in America only 3 people in 100, 000 reach 100．But these Russian old people aren’t alone．The Pakistanis, who live high in the Himalaya Mountains, and the Ecuadorians of the Andes Mountains seem to share the secret of long life, too．
These people remain healthy in body and spirit despite the passage of time．While many older persons in industrial societies become weak and ill in their 60s and 70s, some Caucasians aged 100 to 140, work in the fields beside their great-great-grandchildren．Even the idea of aging is foreign to them．When asked “at what age does youth end?” most of these old people had no answer．Several replied, “Well, perhaps at age 80.”
What accounts for this ability to survive to such old age, and to survive so well? First of all, hard physical work is a way of life for all of these long-lived people．They begin their long days of physical labor as children and never seem to stop．For example, Mr. Rustam Mamedoy is 142 years of age．His wife is 116 years old．They have been married for 90 years．Mr. Mamedoy has no intention of retiring from his life as a farmer．“Why? What else would I do?” he asks．
All these people get healthful rewards from the environment in which they work．They all come from mountainous regions．They live and work at elevations of 1,660 to 1,000 meters above sea level．The air has less oxygen and is pollution-free．This reduced-oxygen environment makes the heart and blood vessel system stronger．
Another factor that may contribute to the good health of these people is their isolation．To a great extent．They are separated from the pressures and worries of industrial society．
Inherited factors also play some role．Most of the longest-lived people had parents and grandparents who also reached very old ages．Good family genes may, therefore, be one factor in living longer．
It is clear that isolation from urban pressures and pollution, clean mountain air, daily hard word, moderate diets, good genes, and a youthful approach to life all contribute to the health and long life of all these people．
1．In the Caucasus region of Russian, how many people can reach the age of 100 in 10,000?
A．5 B．3 C．50 D．10,000
2．The example of Mr. and Mrs. Mamedoy implies that ___________．
A．some Caucasians aged 100 to 140 become weak．
B．some Caucasians aged 100 to 140 are too old to work in the fields．
C．physical work contributes a lot to their long life．
D．some Caucasians aged 100 to 140 are still working in the fields besides their great- great
-grandchildren．
3．What is the main way of life for all of these long-lived people?
A．Retiring from their lives as farmers B．Having been married for 90 years
C．Hard physical work D．No intentions
4．At elevations of 1,220 to 1,000 meters above sea level, the air ______
A．has less oxygen B．is pollution C．is pollution-free D．both A and C
5．The following factors except _________ contribute to the health and long life of all these people．
A．clean mountain air B．daily hard work
C．stress and pressure D．good genes