下列哪组腧穴被称为“四关”穴（）
A.内关、外关
B.合谷、太冲
C.曲池、足三里
D.外关、阳陵泉
E.尺泽、委中
参考答案：B
When we visited Zhangzhuang again ten years later, we found it changed so much that we could
hardly ________ it.[ ]
A. remember
B. think about
C. believe
D. recognize
异频切换一定是硬切换。
