— have you been like this ?—Two days.A. How often B. How long C. How much

问题补充：

— have you been like this ?

—Two days.

A. How often B. How long C. How much

答案：

解析：句意：--你像这样多久了？--两天。A. 多久一次（询问频率）B. 多长时间 C. 多少钱 根据答语two days 为时间段，故用how long 来问。故选B.