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.
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
这题主要考的平行 读完原句要明白,propel 和help boost是平行的,都是这个new type of jet engine 的特性 A平行使用正确,注意that从句是a new type of jet engine 的定语后置,因为太长,放前面显得头重脚轻 BCD,propel 和help boost都不平行 E,have the capability 与could重复