炭疽杆菌之所以引起美国人的恐慌，主要原因之一是它能产生两种成分为蛋白质的内毒素。有的科学家将该菌的大型DNA分子破坏，该菌仍然能产生内毒素。请分析推断，应该破坏该菌的什么结构，才能使它从根本上不再产生内毒素：（   ）

    During my second year of nursing school，our teacher gave us a test.I was a hard﹣working student and I did well1all the subjects.I finished the questions 2until I read the last one，"What is the first name of  the woman3cleans the school？"

    Of course this was only a joke.I saw4 cleaning woman every day.She is short and about 60 years old.

    She has dark hair.5 how would I know her name？I have never talked with her before.In fact，I've never even thought about6to her!I stared at my paper.7 guilty I felt! Finally，I handed in my paper，but the last question 8.

    Before the class ended，one student asked the teacher9the last question would count into our grade.

    "Of course，"the teacher said，"In your life，you will meet10 people.It's important for you 11 them.They deserve（值得）your attention and care，even if all you do is just 12 hello."I'll never forget that lesson.Everyone deserves our attention and we13 try to get to know all the people who work and live around us.That was14 lesson of my life.Later that day，I 15that the cleaning woman's name was Dorothy.

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