为抵抗巷道的侧压，一般情况下，扎角应相当于棚（）长度的1/4～1/5。
参考答案：腿
It is _____ he often fails in exams ________ makes his parents worried about him.
A．what; that
B．that; what
C．that; that
D．/; that
节段型分布的痛觉障碍，无触觉障碍，病变部位在（）
A.脊髓丘脑侧束
B.脊髓丘脑前束
C.后角
D.脊神经节
E.后根
