证券交易都必须按照先时间优先，后价格优先为序的原则进行（）

情景交际（每小题1分，共5分）
根据对话内容，从方框中选择能填入空白处的最佳选项补全对话。
W: Excuse me ,sir.
M:Yes, what can I do for you,madam?
W:I have been here for an hour to meet my father.  小题1:
M:Are you sure of the time his flight arrives?
W:小题2: He told me he would reach the airport at about 1:00 this afternoon.
M:That’s true . Flight BA506 has just arrived.
W:What ?BA506?Well,I don’t think it’s his flight number.
M: 小题3:
W:Yes,it’s VA407. I think ...Oh,just a minute,please. Here   小题4:Sorry, it’s VA408.
M:VA408? I see,madam,the flight should arrive at 1:00,but it will be two hours and twenty minutes late because of the bad wether in New York.
W:Ok.小题5: Thank you very much,sir.
M:Good luck!Madam.

A.But I saw all the passengers come out except him. B.Do you remember his flight number? C.Then I will have to wait longer. D.Yes,I think so. E.I wrote it on my notebook.