标题: 新prep [打印本页] 作者: Jennifer789 时间: 2010-2-22 12:46 标题: 新prep Unlike the short flights of the shuttleand earlier spacecraft, which carried sufficient power in fuel cells and batteries, a permanently orbiting space station will have to generate its own electricity.
A. the short flights of the shuttle and earlier spacecraft, which carried sufficient power in fuel cells and batteries,
B. the shuttle and earlier spacecraft, with sufficient enough power in fuel cells and batteries for their short flights,
C. the short flights of the shuttle and earlier spacecraft, which enabled them to carry sufficient enough power in fuel cells and batteries,
D. the shuttle and earlier spacecraft, which were capable of carrying sufficient power in fuel cells and batteries for their short flights,
E. the flights of the shuttle and earlier spacecraft, whose shortness allowed them to carry sufficient power in fuel cells and batteries,
ans D中的their是指代什么？ 作者: MaverickIris 时间: 2010-2-22 16:40
the shuttle and earlier spacecraft作者: Jennifer789 时间: 2010-2-22 16:43
D中的their是指代什么？