∵复数 z=2i1-i,则z2=(2i1-i)2=-4-2i=-2i,
故选B.
I don’t think fast food is good for our health, so I _______ go to MacDonald. [ ]
A. seldom
B. always
C. usually
D. often
钢丝绳的纵向轴线成螺旋线形状的现象,叫()。
A、波浪形
B、灯笼形
C、扭结
D、弯曲