Was it in the train “ Harmony”, is China’s first high-speed one, that John met with his foreign friend？
A. which
B. that
C. what
D. where
网友回答
(答案→)A. which
B. that
C. what
D. where
解析：本题考查定语从句。先行词为the train “ Harmony”在定语从句中作主语，由于是非限定性定语从句，故只能用which。