題目：Please take a ticket and proceed to the service counter after your
mumber____.
(A) was called
(B) will be called
(C) has been called
(D) will call
疑問：小弟時態很弱，先謝謝各位大大為我解答。
答案是第三個，想問為什麼不是第一個。感很第一個很滿適合的。

"after"在此是連接詞，其所起的子句動作尚未實現，是祈始句的先決條件，不能用過去式，只能用現在式was called (X), is called/ have been called 後者強調完成 (O)另舉例 e.g.: Please turn in your weekly journalto the instructor after you proofread/ have proofread it.