—Could you tell me _________ last night?

—Er, I was watching TV at home.[ ]

A. what you were doing

B. what were you doing

C. what you are doing

D. what are you doing

程序流程图中带有箭头的线段表示的是

A) 图元关系
B) 数据流
C) 控制流
D) 调用关系