A、  B、  C、  C询问过去行为时间的when疑问句→回答过去时间

When will the plant start manufacturing?
(A) In less than 3 months.
(B) The plants are tall and green.
(C) It is located in Mexico.

When did you hand in the annual report?
(A)  It is held once a year.
(B)  Jim will report it tomorrow.
(C)  Yesterday afternoon.