【单选题】根据下面短文内容,回答题。 Pain All of us have felt pain. We have cut ourselves. We have been burned. Or we have had headaches. Some of us suffer pain rarely pain rarely. __________ (46) Pain can take complete con...
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 t.he brain