雅思阅读实战：Biomimetics

雅思阅读实战：Biomimetics,标签：雅思阅读评分标准与雅思阅读真题下载,http://www.xuehuiba.com

　　The next test was whether the array could detect vortices left in the wake of escaping prey. The “prey”， in this case， was a cylinder with water flowing around it. This time， the artificial lateral-line system could work out the general direction of the source and identify the pattern of the vortices. Much like weather vanes in whirlwinds， some sensors in a vortex receive water flowing one way while those on the other side find it flows in the opposite direction. Those in the middle are left unruffled， in the eye of the storm.

　　Section F

　　Having proved his point， Dr Liu is now trying to design sensors that work more like the sense cells in a real lateral line. Instead of heated filaments， these sensors have artificial hairs. The hairs flutter in moving water as flags do in moving air， and the way in which they flutter contains information about the direction and speed of the water moving past them. This principle should allow the team to build more sensitive arrays. Heating filaments in water causes bubbles to form， so turning the power up too much stops them working. Hair sensors do not suffer from the same upper limit.

　　Section G

　　Artificial lateral lines would have many applications. The most obvious would be in submarines， both manned and unmanned. In the case of military submarines they would have the advantage over sonar of being passive. Sending out a ping is a dead giveaway—literally so， in time of war. And merely listening for sound cannot detect stationary threats. A lateral-line system could. The vortices thrown off by water moving past even a stationary object would be visible to it.

　　Dr Liu also speculates about using lateral lines to detect air-movements. That could lead to some far less obvious applications， such as a lateral line-enabled iPod that automatically pumps up the volume in response to the onrushing air of an underground train or similar big， noisy object. That would， indeed， be an inventive brush with nature.

　　Questions 7-12

　　Do the following statemets reflect the claims of the writer in Reading Passage 1？

　　In Boxes 7-12 on your answer sheet write

　　TRUE                      if the statemenht reflets the claims of the writer

　　FALSE                     if the statement contradicts the claims of the writer

　　NOT GIVEN    if it is possbile to say what the writer thinks about this

　　7  Inventors have long counted on the skies and the land rather than the sea to provide new ideas for their inventions.

　　8  Unlike submarine， fish uses the familiar human senses of sight and sound to build images of their surroundings.

　　9 The cells in the natural lateral-line system can detect water movements which are not immediately noticeable.

　　10 Like any other shoaling fish， a small blind salman can still follow its mates without losing its way in water.

　　11 The most obvious application of the artificial lateral lines would be only in human-operated submarines in the future.

　　12 An artifical lateral-line system could detect the existence of the vortices caused by water passing even a motionless object.

　　Questions 13-14

　　Choose the appropriate letters A-D and write them in boxes 13-14 on your answe sheet.

　　13    According to the information in the text， which of the following statements describes the relationship between speed and amount of heat lost in Dr.Liu‘s artificial lateral-line system？

　　A    When the water moved at a faster pace， it took longer time for the heated filaments to lose their heat.

　　B     If the water moved very slowly past a heated filament， the filament would lose its heat fairly rapidly.

　　C    The speed of water moving past a heated filament was in direct proportion to the amount of heat it lost.

　　D     The speed of water moving past a heated filament was inversely proportional to the amount of heat it lost .

　　14    According to the information in the text， which of the following statements is NOT the charateristics of the natural lateral-line system in Dr.Liu‘s tests on the artifical version of a fishy sense organ ？

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