---Let’s back up. Where was I?---You about the trip to South Africa.A. were talking B. tal

问题补充：

---Let’s back up. Where was I?

---You about the trip to South Africa.

A. were talking

B. talked

C. are talking

D. would talk

答案：

(答案→)A. were talking

B. talked

C. are talking

D. would talk

解析：考查时态。句意：—我们回顾一下。我讲到哪里了？—你正讲到去南非的旅行。根据句意说明询问的是在过去的某个时间点上正在发生的事情，所有使用过去进行时的时态。故A正确。