题目

I often dreamed about Pisa when I was a boy．I read about the famous building called the Leaning Tower of Pisa．But when I read the word Pisa，I was thinking of pizza．I thought this tower was a place to buy pizza．It must be the best place to buy pizza in the world，I thought． Many years later I finally saw the Leaning Tower．I knew then that it was Pisa and no pizza．But there was still something special about it for me．The tower got its name because it really does lean（倾斜）to one side．Some people want to try to fix（修理）it．They are afraid it may fall over and th能够分解水中有机物达到净化污水作用的细菌是（ ）A．乳酸菌B．甲烷菌C．醋酸菌D．大肠杆菌