—What time do we have to be at the gate?— passengers start to board the plane.A. Hurriedl

问题补充：

—What time do we have to be at the gate?

— passengers start to board the plane.

A. Hurriedly

B. Soon

C. Immediately

D. Since

答案：

A. Hurriedly

B. Soon

(答案→)C. Immediately

D. Since

解析：immediately此处用作连词，引导时间状语从句，相当于as soon as。