Brian was about to when he suddenly found an answer to the question.A. make up　　B. look up

问题补充：

Brian was about to when he suddenly found an answer to the question.

A. make up

B. look up

C. turn up

D. give up

答案：

A. make up

B. look up

C. turn up

(答案→)D. give up

解析：句意：布莱恩正要放弃，这时他突然发现了问题的答案。根据句意正在这时突然找到了答案，说明当时正没有办法解决问题，所以说快要放弃了。 make up组成，化妆，编造；look up仰望，查阅，尊敬； turn up出现，发生，开大； give up放弃，停止。故选D。