Since 1945 the United States had entered a twenty-five-year period of economic boom, but its ______ industry did not experience great development.
A、automobile
B、aerospace
C、housing
D、defense
【正确答案】：B
【题目解析】：自1945年以来，美国进入了25年的经济繁荣时期，但其航空航天工业并没有得到很大的发展。
