题目

阅读理解Mr. Hadleywas my 6th grade teacher. At that time I was a short girl weighing 70kilograms. Boys always laughed at me because of it. So I became an extremelyshy young lady.One dayMr. Hadley told us that we would be required to come to the front of the classand read the reports that we had completed.When myturn came, I refused to stand in front of all those students and open up totheir tricks. Mr. Hadley handed me my report and asked me to read it. I gave itback to him. He walked to the font and said, “Martha has a very good reporthere and I think everyone needs to hear her read it.传染源指的是（ ）A．能够传播的病原体B．被污染了的环境C．能够散播病原体的人或动物D．病人的排泄物或分泌物