问题
选择题
With the successful launch of Tiangong-I, which was ______ breakthrough in space field, China's space dream took a step closer to ______ reality.
A. a; / B. the; a C. a; the D the; /
答案
A
题目分析：句意：随着航空领域的一大突破天宫一号的成功发射，中国的太空梦朝现实更迈进了一步。第一空填a，泛指这是一个突破，第二空不填，reality是抽象名词，选A。
