GRE考试

根据网考网考试中心的统计分析，以下试题在2018/1/9日GRE考试习题练习中，答错率较高，为：78%
【单选题】The development of a thoroughly effective treatment for narcolepsy is regarded by the author as


A．possible, but not very important
B．interesting, but too costly to be practical
C．promising, but many years off
D．extremely unlikely
E．(E) highly probable