A、  B、  C、  C题目为询问这些设备是否在贸易博览会上展览的Be动词疑问句。

Didn’t we extend the deadline until Friday?
(A) We’re expanding the company.
(B) No, it’s Thursday.
(C) We’d better set a deadline.

Are these devices on display at the trade show?
(A) It was an amazing show.
(B) I’ll devise a plan for you.
(C) Yes, they’re at our booth.