题目

设ω=+i,则ω2等于A.1                   B.ω                  C.                    D. 答案：C  ω2=(+i)2=i=i=. －What ________ your English teacher doing now? －He ________ a newspaper． [　　] A． is, reading B． is, is looking at C． does, watching D． is, is reading