GWD13-Q6，帮忙看一下！

labixiaoxinyue

Q6:
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
答案是E，可是我觉得could 和have the capability是语义重复的呀！很弄不懂，求解答！

jameshzd

不选E没得别的选啊~E是最好的~
然后个人觉得 eventually 这里是来强调 它最终有这个能力去干什么。

adamjcw

A 定语从句修饰错误B 同A
C，D 平衡错误
E

labixiaoxinyue

谢谢！明白了！