Armstrong became interested in ever since he took his first at the age of six.A. fly; fl

问题补充：

Armstrong became interested in ever since he took his first at the age of six.

A. fly; flying

B. flight; fly

C. flight; flying

D. flying; flight

答案：

A. fly; flying

B. flight; fly

C. flight; flying

(答案→)D. flying; flight

解析：句意：阿姆斯特朗自从六岁时开始第一次飞行就对飞行产生了兴趣。Fly是动词“飞，飞行”，become interested in“对 ……感兴趣”，后接名词、代词、动词ing；flight是其名词形式，在句中作主语或宾语。故选D。