Question

the groundhog and its shadow
can animals guess the weather? groundhog day is a custom based on the idea that they can. in early february, people start wondering how much longer winter will last. an old story says that groundhogs give us the answer on february 2. they say that if a groundhog leaves its hole on groundhog day and sees its shadow, it will go back underground to sleep more. that means there will be six more weeks of winter. if there is no shadow, the groundhog stays above ground. people believe this means spring is near.
what is the main, or central, idea of the passage?
february 2 is a day when sleeping animals come out of their holes and stay above ground.
groundhog day is a holiday to celebrate the end of winter.
some people believe that groundhogs can tell us when winter will end.

Explanation:

The passage starts by asking if animals can guess the weather and then introduces Groundhog Day. It explains the old story that groundhogs give the answer about winter's end on February 2. If a groundhog sees its shadow, there are six more weeks of winter; if no shadow, spring is near. So the main idea is about people's belief that groundhogs can tell when winter will end.

Answer:

Some people believe that groundhogs can tell us when winter will end.