Read the passage. There are several questions about this passage.
whether formed by water run-off, deer, or wild turkey, every path seemed to
be a desire path.
2
But when we were some hundred feet below the ridge line, the signal
picked up, and its steady, loud chirping took us to the old black locust tree,
seventy or maybe seventy-five feet tall, with cracks and fissures in its deeply
furrowed bark that made it an accommodating roost. A pamphlet from the US
Fish and Wildlife Division of the Department of Environmental Conservation
describes the Indiana bat as having fur that is "dull grayish chestnut rather
than bronze, with the basal portion of the hairs of the back dull lead colored.
This bat's underparts are pinkish to cinnamon, and its hind feet small and
delicate." I saw nothing like this, but when we listened very carefully, we could
hear their hum of gentle chattering. Bats use sound to situate themselves;
their capacity for echolocation is what guldes them, what elucidates their
sense of space and substance, what locates their prey. But the sound, a series
of tiny clicks ten or twenty, forty or even two hundred times a second, is at a
frequency beyond most human hearing; it is exactly that high frequency with
its short wavelengths that produces the detailed echoes the bats rely on to
learn the shape of their universe. We live in an acoustical empire we will never
know, our threshold of hearing situated somewhere between the low,
Infrasonic rumbling of elephants and the high-pitched ultrasonic rasping of
tenrec shrews that rub their quills together to communicate. I knew that the
subtle whispering I could make out was but a fraction of the sound sensation
the bats were creating and, listening to the soft murmuring, felt I was standing
at the gate to a remote kingdom of sound that could only be imagined.
In paragraph 2, how are elephants and tenrec shrews
related to the human "threshold of hearing"?
1. These animals illustrate the lowest and highest
sounds that most humans can hear.
2. These animals make some sounds that are
outside the range of human hearing.
3. These animals can hear sounds that most
humans and bats are also likely to hear.
4. These animals are like humans in their ability to
hear the range of sounds made by bats.