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 Answer: E
我觉得E选项的capability to do不对，应该用capability of doing sth.,记得上XDF课程时讲过ability才搭配to do. 不知其他人有无同感? | 
