题干
Jack is late again. It is ______ of him to keep others waiting.
A：normal
B：ordinary
C：common
D：typical
答案(点此获取答案解析）
D
Jack is late again. It is ______ of him to keep others waiting.
A：normal
B：ordinary
C：common
D：typical
是虚数单位，复数
的共轭复数是
，若
，则