标题: XDF SC 4-12 [打印本页] 作者: CasualWalk 时间: 2003-5-23 15:50 标题: XDF SC 4-12 Most nations regard their airspace as extending upward as high as an aircraft can fly; no specific altitue, however, has been officially recognized as a boundary.
a) as extending b) as the extent c) to be an extent d) to be an extension e) to extend
肯定是a or b, 但我觉得a,b都不顺。答案为A。请指点一下extending在这里的用法， 谢谢！作者: 1stzhang 时间: 2003-5-23 17:16
upward是副词，所以不能用extent作者: CasualWalk 时间: 2003-5-24 13:53
I see. 谢谢。