. All of the guests by 9 o’clock but the host until 15 minutes later .A. arrived; didn

问题补充：

. All of the guests by 9 o’clock , but the host until 15 minutes later .

A. arrived; didn’t turn up

B. had arrived; didn’t turn up

C. arrived; hadn’t turned up

D. had arrived; hadn’t turned up

答案：

A. arrived; didn’t turn up

(答案→)B. had arrived; didn’t turn up

C. arrived; hadn’t turned up

D. had arrived; hadn’t turned up

解析：本题对过去发生的动作的陈述，客人的到来发生在主人的到来之前。故选B