--Did you call Sara back ? ----I didn’t need to we’ll have a meeting together tonight

问题补充：

----Did you call Sara back ?

----I didn’t need to , we’ll have a meeting together tonight.

A. though .

B. unless

C. because

D. if

答案：

A. though .

B. unless

(答案→)C. because

D. if

解析：连词辨析。Though虽然，尽管；unless除非；because因为；if是否，如果。句意：你喊萨拉回来了吗？——我不必。因为我们今晚一起有个会议。故选C。