There are thousand of pigeons in any big city in the world. (1) __________________________________? Just how pigeons find their way home is a bit of mystery. Some people think that they use landmarks that is the pigeon knows what the land is like from the air and it uses this like a map. (2) _______________________________________, which can easily be seen from a long way off. Other possibilities are that pigeon use the position of the sun to work out directions or that they have some kind of built in compass. (3) ____________________________________ but they still aren't to sure how pigeons find their way home. It seems likely however that pigeons like airline pilot use a number of different methods to guide them on their long distance journeys. Perhaps, one day we'll learn their secret.
发表于 2015-10-30 11:18
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