放久的馒头会长出“白毛”或“黑毛”，“白毛”或“黑毛”属于霉菌，它们来自（ ）

    Patricia is a pianist and music teacher in California.She wanted to1money for music scholarships at her local community college.One day she had an idea.She thought，"I'm going to ride my2across the United State this summer.I'm going to ask people to give money3 every mile I ride."She talked to the people in the community about4idea. They all liked the idea and strongly supported her.So she felt very5for it.

    Patricia joined about forty other6who were all from California.They began the long 7 across the US in Astoria，Oregon.Patricia went up and down huge hills.She saw beautiful countryside and8friendly people.9there were problems，too.The 10was sometimes very hot，windy or cold.Patricia was tired and sore every night.

    One day she11an accident.She12her bike and her toes were badly hurt.But she continued to ride.She overcame many difficulties and spent two13on the whole ride.She raised more than $10，000 for music scholarship.Patricia was happy and14of it. She did it!

    People don't 15her when she tells them her age.Patricia looks very young and  acts very young.Can you imagine that she is 67 years old? The 67-year-old woman rode across the US in sixty days !