题干
Mike will go abroad tomorrow. I am going to _____ at the airport.
A：sent him off
B：saw him off
C：see off
D：see him off
答案(点此获取答案解析）
D
Mike will go abroad tomorrow. I am going to _____ at the airport.
A：sent him off
B：saw him off
C：see off
D：see him off
的方程
有实根
，复数
，则复数
在复平面内的对应点到原点的距离为