The Japanese Macaca monkey has been studied in the wild for over 50 years. In 1952, on one small Japanese island, scientists dropped some   36   dirt for the monkeys. The monkeys liked their taste, but they found the dirt   37 .
One clever 18-month-old monkey    38  the problem by washing the sweet potatoes in a nearby river, She taught this to her mother. Her   39  also learned this new way and they taught their mothers too.
All the younger monkeys   40  learned to wash the dirty sweet potatoes to make them   40  to eat. But many found it very hard to learn this and still ate the   42  sweet optatoes.
Then something very    43  . In the autumn of 1958, scientists found that the monkeys on other nearby   44  began washing their sweet potatoes too. Scientists still don’t fully understand how this knowledge was   45  from one island to another.

Never try to work when you are very hungry .If you   36  your homework right after school, you may want to have a snack before getting to work. Always do your homework       37   you get tired.____38____wait until very late in the evening ,or the assignment(功课)will seem much  39  than it really is .Break your time into manageable(易处理的) period .If you have more than  40，give yourself a break after an hour .On the other hand ,don't break it up _41  that you can’t get anything done .You should be able to work at least half an hour at a time  42  .Don't put it off  43   the last minute .If you put off doing your homework ,you will always think of it ,and you won’t enjoy your  44   so much .If you put it off until the end of the week  until right before a test ,you will have too much work to do for the exam .A little bit each night ,enough to keep up with what is happening each day in school ,will take the fear out of tests and keep you on top of it all .Do your hamework__45  every day .This will help you make it a habit .It will make it easier to do ,and it will make free time more enjoyable as well.

The Japanese Macaca monkey has been studied in the wild for over 50 years. In 1952, on one small Japanese island, scientists dropped some   36   dirt for the monkeys. The monkeys liked their taste, but they found the dirt   37 .

One clever 18-month-old monkey    38  the problem by washing the sweet potatoes in a nearby river, She taught this to her mother. Her   39  also learned this new way and they taught their mothers too.

All the younger monkeys   40  learned to wash the dirty sweet potatoes to make them   40  to eat. But many found it very hard to learn this and still ate the   42  sweet optatoes.

Then something very    43  . In the autumn of 1958, scientists found that the monkeys on other nearby   44  began washing their sweet potatoes too. Scientists still don’t fully understand how this knowledge was   45  from one island to another.

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The Japanese Macaca monkey has been studied in the wild for over 50 years. In 1952, on one small Japanese island, scientists dropped some   36   dirt for the monkeys. The monkeys liked their taste, but they found the dirt   37 .

One clever 18-month-old monkey    38  the problem by washing the sweet potatoes in a nearby river, She taught this to her mother. Her   39  also learned this new way and they taught their mothers too.

All the younger monkeys   40  learned to wash the dirty sweet potatoes to make them   40  to eat. But many found it very hard to learn this and still ate the   42  sweet optatoes.

Then something very    43  . In the autumn of 1958, scientists found that the monkeys on other nearby   44  began washing their sweet potatoes too. Scientists still don’t fully understand how this knowledge was   45  from one island to another.

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