关节脱位的特有体征是（）
A.肿胀
B.疼痛
C.功能障碍
D.异常活动
E.关节囊空虚
参考答案：E
通过立井导入高程的实质是求（）。常用的方法有（）及（）。
—Mr Wang, I have trouble ________ the text.
—I'm sure you can, but remember ________ it at least three times. [ ]
A. to understand; reading
B. understanding; reading
C. to understand; to read
D. understanding; to read
