66．What did they these teenagers learn from the
journey?
A．It was
high time that people protected the environment.
B．Long
journey was not suitable for school children.
C．It
should take the whole world to help the children.
D．Environmental
problems can be solved if school children take part.
D
How much can environment affect intelligence? In one study, striking increases in IQ
occurred
in 25
children who were moved from an orphanage(孤儿院) to more
stimulating(使人兴奋的，使人振奋的) environments．The
children, who were all considered mentally retarded and unadoptable, were moved
to an institution where they received personal attention from adults．Later,
these supposedly retarded children were adopted by parents who gave them love,
a family ,and a stimulating home environment．The children
gained an average of 29 IQ points．For one child, the
increase was an amazing 58 points．A second group of
initially less "retarded" children, who stayed in the orphanage, lost
an average of 26 IQ points.
Other encouraging
results can be found in early childhood education programs, which provide
stimulating
intellectual experiences for disadvantaged children．In one
study, children from low-income families were given enriched environments from
early infancy(婴儿期) through preschool．By age
2 their IQ scores were already higher than those in a control group．More
important, they were still 5 points higher seven years later．High-quality
enrichment programs such as Head Start can prevent children from falling behind
in school.
A particularly
striking environmental effect is the fact that 14 nations have shown average IQ
gains
of from 5 to 25 points during the last 30 years．These IQ boosts,
averaging 15 points, occurred in far too short a time for genetics to explain
them．It is more likely that the gains reflect environmental forces, such as
improved education, nutrition, and living in a technologically complex society.