高中英语人教版高三2 08

[06:41.55]Von Frisch and his coworkers set up a feeding place close to the hive.
[06:49.21]Then they slowly moved it farther and farther away.
[06:55.16]Back at hte hive they watched the wagging dance closely.
[07:01.22]With a stopwatch,
[07:04.88]they counted how many times the bees repeated the dance during one minute.
[07:12.54]They discovered that the farther away the feeding station was,
[07:18.78]the slower the dance was.
[07:23.32]So another astonishing fact came to light .
[07:28.99]The number of wagging dances per minute
[07:33.96]told the exact distance to the feeding place.
[07:39.00]They also found out that bees fly a maximum distance
[07:45.97]of 3.2 kilometres between their hive and a feeding place.
[07:52.63]Next Von Frisch thought that bees needed to know more than just the distance
[08:00.29]to a faraway place.
[08:03.63]He thought they needed to know the direction to it.
[08:08.31]He set out to discover whether the wagging dance showed direction.
[08:15.26]He put a glass dish with sugar water and honey to the west of the hive.
[08:22.91]A marked bee fed itself from the dish and returned to the hive.
[08:30.17]Soon,the bees in the hive flew out.They flew right to the dish.
[08:37.43]Then Von Frisch moved the dish to the east of the hive
[08:43.21]and waited for a marked bee to feed.
[08:48.07]Again the bees flew right to the dish.
[08:53.32]How did the bees know exactly in which direction to fly?
[08:59.27]Von Frisch watched the wagging dance very carefully.
[09:05.83]He noticed that the straight part of the dance was different in the afternoon
[09:12.67]from what it had been in the morning.
[09:17.11]It soon became clear that the straight part of the dance
[09:22.86]changed when the sun's position changed.
[09:27.69]If the feeding place was toward the sun,
[09:32.84]the dancer headed straight upward during the straight part of the wagging dance.
[09:39.92]If the feeding place was away from the sun,
[09:45.06]the straight part of the wagging dance pointed downward.
[09:50.63]The wagging dance of the honey bee,therefore,
[09:55.36]did show the direction of a feeding place.
[10:00.03]When honey bees have discovered a feeding place,
[10:05.07]they fly directly to it from the hive.
[10:09.83]After a short time a line of bees fly to and from the hive like a thin stream.
[10:18.89]Centuries ago,the word"beeling"
[10:24.35]was made to describe this thin line of bees flying through the air.
[10:30.62]From this we get the expression"to made a beeline for someone or something",
[10:38.17]which means to go quickly along a straight direct course for someone or something.
[10:46.64]For his lifetime's work in studying the communication of animals,
[10:52.80]including honey bees,
[10:56.74]Professor Karl von Frisch was given a Nobel Prize in 1973,
[11:04.50]which he shared with two other scientists.He died in 1982.