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, 少谓语 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 that修饰jet engine 限定性定语从句 不能分开 Q10: Marconi’s conception of the radio was as a substitute for the telephone, a tool for private conversation; instead, it is precisely the opposite, a tool for communicating with a large, public audience. - Marconi’s conception of the radio was as a substitute for the telephone, a tool for private conversation; instead, it is
- Marconi conceived of the radio as a substitute for the telephone, a tool for private conversation, but 少主语 谓语 which is
- Marconi conceived of the radio as a tool for private conversation that could substitute for the telephone; instead, it has become
- Marconi conceived of the radio to be a tool for private conversation, a substitute for the telephone, which has become
- Marconi conceived of the radio to be a substitute for the telephone, a tool for private conversation, other than what it is,
it, which 指代不清 other than what it is 从形式可以判断出 it指代radio |