One day a farmer’s donkey fell down into a well. The animal cried piteously for hours as the farmer tried to figure out what to do. Finally, he decided that the animal was old, and the well needed   31  (cover) up anyway; the donkey just wasn’t worth saving.

He invited all his neighbors to come over and help   32 . They all took a shovel (铲) and began to shovel some dirt into the well. At first, the donkey realized   33  was happening and cried   34  (terrible). Then, to everyone’s amazement, he quieted down. A few shovel loads later, the farmer finally looked down the well. He   35  (astonish) at what he saw. With each shovel of dirt   36  hit his back, the donkey was doing something   37  (amaze). He would shake it off and take a step up.

  38  the farmer’s neighbors continued to shovel dirt on top of the animal, he would shake it off and take one more step up. Pretty soon, everyone was amazed as the donkey stepped up over   39  edge of the well and happily ran off!

Each of our troubles is a steppingstone. We can get out of the deepest wells just   40  not giving up! Shake it off and take a step up.

氯霉素可发生的一种与剂量无关的不良反应是

A．二重感染

B．不可逆的再生障碍性贫血

C．治疗性休克

D．可逆性各种血细胞减少

E．灰婴综合征