阅读理解
in 1953, a mountain climber reported seeing
a bar-headed goose soar over the peak of mount everest (珠穆朗玛). it
was thought impossible. now researchers who raised 19 of the geese—named for the black stripes on the backs of their heads—have shown the birds really fly so high.
the team trained the youngsters
to fly in a large wind tunnel wearing backpacks and face masks full of sensors
that recorded their heart rate. blood oxygen levels, temperature, and metabolic
rate—how many
calories they burned per hour. the researchers simulated(模拟)10w-, medium-, and high-altitude conditions by altering the
concentration of oxygen supplied to face masks worn by each goose as it flew in
the tunnel.
birds already have a better
heart and lungs than mammals for sustained physical activity. and researchers
knew that bar-headed geese have even larger, thinner lungs that let them
breathe more deeply and an even bigger heart to pump more oxygen to muscles
than other birds.
in 1953, a mountain climber reported seeing
a bar-headed goose soar over the peak of mount everest (珠穆朗玛). it
was thought impossible. now researchers who raised 19 of the geese—named for the black stripes on the backs of their heads—have shown the birds really fly so high.
the team trained the youngsters
to fly in a large wind tunnel wearing backpacks and face masks full of sensors
that recorded their heart rate. blood oxygen levels, temperature, and metabolic
rate—how many
calories they burned per hour. the researchers simulated(模拟)10w-, medium-, and high-altitude conditions by altering the
concentration of oxygen supplied to face masks worn by each goose as it flew in
the tunnel.
birds already have a better
heart and lungs than mammals for sustained physical activity. and researchers
knew that bar-headed geese have even larger, thinner lungs that let them
breathe more deeply and an even bigger heart to pump more oxygen to muscles
than other birds.
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