请问885-04-12&23 12. Most nations regard their airspace as extending upward as high as an aircraft can fly; no specific altitude, 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 这题划线的UPWARD不在A里, 我想问,B选项为什么不对? 原文划线部分怎么理解才好呢?

extingding应该是adj吧，什么叫regard sth as adj as adv as....

请问这句话是什么意思啊谢谢

extending 是动名词啊，不是adj。 这里应该把extending upward 看成一个整体吧

B， extent 是名词，怎么与upward连用啊？ ？