Dog owners, who have noticed that their four – legged friend seems equally delighted to see them after five minutes away as five hours, may wonder if animals can tell how much time passes. Newly published research from The University of Western Ontario may bring us closer to answering that very question.

       William Roberts and his colleagues found that rats are able to keep track of how much time has passed since they discovered a piece of cheese,  be it a little or a lot ,but they don’t actually form memories of when the discovery occurred .That is ,the rats can’t place the memories in time.

The research team designed an experiment in which rats visited the ‘arms’ of a maze（迷宫） at different times of day. Some arms contained common desirable food, and one arm contained a highly desirable piece of cheese .Rats were later returned to the maze with the cheese removed on certain trials and replaced with something else.

       All told ,three groups of rates were tested in the research using three varying cues （提示，暗示）: when , how long ago or when plus how long ago.

       Only the cue of how long ago food was encountered（偶遇）was used successfully by the rats.

       These results , the researchers say ,suggest that episodic（片段的）memory in rats is quite different from human episodic memory ,which involves exact memory of the point in past time when as event occurred.

       “The rats remember whether they did something, such as stored food a few hours or five days ago,” explained Roberts. “The more time that has passed, the weaker the memory may be. Rats may learn to follow different courses of action using weak and strong memory traces as cues ,thus responding differently depending on how long ago an event occurred .However , they do not remember that the event occurred at a specific point in past time.”

       “This research,” said Roberts, “supports the theory I introduced that animals are stuck in time, with no sense of time extending into the past or future.”

1．The research team found       .

       A．rat’s memory has no difference from human’s

       B．rats can remember all the events in the past

       C．animals are stuck in time with little idea of past or future

       D．rats have sense of time extending into the past or future

2．Put into a maze ,rats can remember       .

       A．when they encounter the cheese

       B．how long ago they encounter the cheese

       C．where the cheese is

       D．which “arms” they have been to

3．The test shows that         .

       A．the more time has passed ,the stronger the rats’ memory may be

       B．rats can keep track of the time when the discovery occurred

       C．the cue of how long ago the discovery occurred works well on rat’s memory

       D．dog owners still can’t know if animals can tell how much time passes

4．Which column may this passage appear in a magazine?

       A．Science.              B．Health.                C．Sports.                D．Business.

5．From the passage ,we can know that       .

       A．episodic memory in rats is based on when not how long ago

       B．humans can place the memories in time

       C．human episodic memory is similar to rats’

       D．only rats have no sense of time extending into past and future

Dog owners，who have noticed that their four—legged friend seems equally delighted to see them after five minutes away as five hours，may wonder if animals can tell how much time passes．Newly published research from The University of Western Ontario may bring us closer to answering that very question．

    William Roberts and his colleagues found that rats ale able to keep track of how much time has passed since they discovered a piece of cheese，be it a little or a lot，but they don’t actually form memories of when the discovery occurred．That is，the rats can’t place the memories in time．

    The research team designed an experiment in which rats visited the ‘arms’ of a maze（迷宫）at different times of day．Some arms contained common desirable food，and one arm contained a highly desirable piece of cheese．Rats were later returned to the maze with the cheese removed on certain trials and replaced with something else．

    All told，three groups of rates were tested in the research using three varying cues（提示，暗示）：when，how long ago or when plus how long ago．

    Only the cue of how long ago food was encountered（偶遇）was used successfully by the rats．

    These results，the researchers say，suggest that episodic（片段的）memory in rats is quite different from human episodic memory，which involves exact memory of the point in past time when as event occurred．

    “The rats remember whether they did something，such as stored food a few hours or five clays ago，”explained Roberts．“The more time that has passed，the weaker the memory may be．Rats may learn to follow different Courses of action using weak and strong memory traces as cues，thus responding differently depending on how long ago all event occurred．However，they do not remember that the event occurred at a specific point in past time．”

    “This research，”said Roberts，“supports the theory I introduced that animals are stuck in time．with no sense of time extending into the past or future．”

1．The research team found ________．

    A．rat’s memory has no difference from human’s

    B．rats can remember all the events in the past

    C．animals are stuck in time with little idea of past or future

    D．rats have sense of time extending into the past or future

2．Put into a maze，rats can remember ________．

    A．when they encounter the cheese

    B．how long ago they encounter the cheese

    C．where the cheese is

    D．which “arms” they have been to

3．The test shows that ________．

    A．the more time has passed，the stronger the rats’ memory may be

    B．rats can keep track of the time when the discovery occurred

    C．the cue of how long ago the discovery occurred works well on rat’s memory

    D．dog owners still can’t know if animals earl tell how much time passes

4．Which column may this passage appear in a magazine?

    A．Science．            B．Health．              C．Sports．         D．Business．

5．From the passage，we can know that ________．

    A．episodic memory in rats is based on when not how long ago

    B．humans call place the memories in time

    C．human episodic memory is similar to rats’

    D．only rats have no sense of time extending into past and future