A.2^－2k                                                              B.2^－(2k－1)

C.－2^－(2k+1)                                                     D.2

－2与－的大小关系是______________．

－2与－的大小关系是______________．

A.2＋i              

B.2－i               

C.－2＋i                         

D.－2－i