第五部分：补全短文(第46～50题，每题2分，共10分)
阅读下面的短文，文章中有5处空白，文章后面有6组文字，请根据文章的内容选择5组文字，将其分别放回文章原有位置，以恢复文章原貌。请将答案涂在答题卡相应的位置上。
A．And others have painful attacks all the time.
B．These signals travel from nerve cells in the injured area, up the spinal cord (脊髓) to the brain, and back down again.
C．It tells us that we are injured and should do something about it.
D．They knew little about the process of pain itself.
E．The other message moves at a speed of only one meter a second.
F．And they send the second, slower message of pain to the brain.