UCLA scientists report for the first time on the only known frog species that can communicate using purely ultrasonic(超声）calls, whose frequencies are too high to be heard by humans. Known as Huia cavitympanum, the frog lives only on the Southeast Asian island of Bomeo(婆罗洲）.
Ultrasounds are high-pitched sounds more than  20 kilohertz(kHz) in frequency, which exceeds the upper limit of sounds detectable by humans and is far higher than the 5 to 8 kHz frequencies most amphibians (两栖动物)，reptiles and birds are capable of hearing or producing. Key parts of the ear must be specially adapted to detect ultrasounds.
The frogs can hear sounds up to  38 kilohertz, the highest frequency that any amphibian species has been known to hear, the scientists report. Humans can hear up to about  20 kHz and typically talk at 2 or 3 kHz.
While most of the more than 5，000 frog species worldwide have eardrums that are flat on the side of the head, Huia cavitympanum has eardrums recessed in the side of the skull, similar to mammals.
Peter Narins, UCLA distinguished professor of physiological science and of ecology and evolutionary biology, and Victoria Arch, a UCLA graduate student in ecology and evolutionary biology, spent several nights in the remote area where the frogs live.
" We had very little information suggesting that they would be in this location，" said Arch, lead author of the study. " We found them our first night out. "
The study was published on April  29 in the online journal PLOS ONE, a publication of the Public Library of Science, and is available at
http://dx. plos. org/10. 1371/journal, pone. 05413.
Huia cavitympanum mainly live __________.

A．in all over the world

B．in many parts of China

C．only on the Southeast Asian island of Borneo

D．only on the certain countries' marsh

This kind of new-found frog can hear each other with up to __________ kHz ultrasounds.

A．2-3	B．5 -8
C．more than 20	D．38

If people can hear ultrasounds as frogs do, they should    __________.

A．hear as frogs do carefully

B．have a pair of good enough ears like frogs

C．concentrate their energy on them

D．turn them into common sounds

According to the passage we can infer that __________.

A．the result of study is concluded not easily

B．some scientists have done a lot of work for the result

C．all the frogs have the ability with 38 kHz frequency

D．this kind of frogs is as important as animals

This passage probably appears __________.

A．on the newspaper	B．on the textbook
C．on the website	D．on the report