The Meglev Train travels in a vacuum between two magnets, no pollution is caused and less energy is consumed.
A. where
B. which
C. when
D. therefore
网友回答
A. where
B. which
C. when
(答案→)D. therefore
解析：句意辨析。句意：磁悬浮列车是在两个磁铁间运行的，因此不会导致污染，也没有消耗什么能源。根据句意说明上下文是因果关系，therefore就是表示因果关系，故D正确。