点A与点B关于直线a对称,则直线a垂直线段AB,且平分线段AB。[ ]
正确
His brother ___ the Party about five years ago.
A.joined
B.joined in
C.has joined
D.has joined in
鼻咽癌患者远处转移,最常见的组织是()。
A.骨
B.肺
C.肾
D.脑
E.肝脏