高血钾的心电图主要特点是（）
A.U波倒置
B.QRS波群增宽
C.ST段水平下移
D.T波倒置
E.T波高耸变尖，基底部狭窄，呈帐篷型T波
参考答案：E
-Where is Miss Lee, do you know?
-_____ she is in the library. She said she wanted to borrow some books.[ ]
A. Maybe
B. May be
C. May
D. Must
简述锚杆支护挤压加固拱作用原理？
