外阴血肿，宜选用下述何种外治法( )
A． * * 纳药
B．介入治疗
C．外阴冲洗
D．坐浴
E．贴敷
参考答案：E
At the beginning ofleaming English, I had a lot of trouble _____with other people in it. [ ]
A. communicate
B. to communicate
C. communicating
若任一n维非零列向量都是n阶矩阵A的特征向量，证明A是数量矩阵(即A=kE，E是n阶单位矩阵).
