Q23: GWD-11-33

Q23: GWD-11-33

After more than four decades of research and development, a new type of jet engine is being tested that could eventually propel aircraft anywhere in the world within two hours or help boost cargoes into space at significantly lower costs than current methods permit.

A.     tested that could eventually propel aircraft anywhere in the world within two hours or help

B.     tested that could eventually have the capability of propelling aircraft anywhere in the world within two hours or to help

C.     tested, eventually able to propel aircraft anywhere in the world within two hours, or helping

D.    tested, and it eventually could propel aircraft anywhere in the world within two hours or helping

E.     tested, and it could eventually have the capability to propel aircraft anywhere in the world within two hours or help

选A  我觉得E也对啊

而且A说that定语从句后置，that定语从句后置是什么？实在不明白。。请大家帮忙看看吧

E，could 和 capability重复了

定于从句后置就是说如果定语从句太长的话可以后置，避免头重脚轻。