Hardly had we arrived at the hotel, that there was a power cut. A. had we B. at C. that D. a

C

Cấu trúc: Hardly had + S + Ved/ V3 when/ before S + Ved/ V2 [ ngay khi...thì...]

Câu này dịch như sau: Ngay khi chúng tôi vừa đến khách sạn thì mất điện.

That => when/ before

=>Chọn C