Question

—         have you stayed in Shanghai?
— For about seven days.
A. How soon                   B. How long           C. How often

Answer 1

B

根据答语For about seven days.大约七天了，可推断出上句问的是“你在上海呆了多长时间了？所以选B，How soon 多久，How often 表示频率，多久一次。