托?？荚囌骖}閱讀及答案解析托福真題及答案解析匯總-資料下載頁
2025-08-08 02:32本頁面
【正文】 generate electric fields that sharks can use for orientation and possibly navigation.electric field proximity sensing is used by the electric catfish to navigate through muddy waters. these fish make use of spectral changes and amplitude modulation to determine factors such shape, size, distance, velocity, and conductivity. the abilities of the electric fish to municate and identify sex, age, and hierarchy within the species are also made possible through electric fields. ef gradients as low as 5nv/cm can be found in some saltwater weakly electric fishthe paddlefish (polyodon spathula) hunts plankton using thousands of tiny passive electroreceptors located on its extended snout, or rostrum. the paddlefish is able to detect electric fields that oscillate at –20 hz, and large groups of plankton generate this type of signal. see: electroreceptors in paddlefishelectric fishes use an active sensory system to probe the environment and create active electrodynamics imagingin 1973, it was shown that atlantic salmon have conditioned cardiac responses to electric fields with strengths similar to those found in oceans. this sensitivity might allow a migrating fish to align itself upstream or downstream in an ocean current in the absence of fixed references.magnetoception, or magneto reception, is the ability to detect the direction one is facing based on the earth39。s magnetic field. in 1988, researchers found iron, in the form of single domain magnetite, resides in the skulls of sockeye salmon. the quantities present are sufficient for magnetoceptions(content_relate)。【2017年托?？荚囌骖}閱讀及答案】相關(guān)文章：1.托?？荚囬喿x真題訓(xùn)練及答案2.托福閱讀考試真題及答案3.托?？荚囬喿x真題4.托福閱讀真題及答案：passage 25.托福閱讀真題及答案：passage 36.托福閱讀真題及答案：passage 17.托?？荚囬喿x歷年真題8.歷年托福考試閱讀真題
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