are the days when the teachers were looked down upon .A. GoneB. GoC. To goD. Going

问题补充：

are the days when the teachers were looked down upon .

A. Gone

B. Go

C. To go

D. Going

答案：

(答案→)A. Gone

B. Go

C. To go

D. Going

解析：固定句型：gone are the days when…。