调车作业时,挤道岔为()事故。
A.一般A类
B.一般B类
C.一般C类
D.一般D类
参考答案:D
I’m told that languagepractising.com is a free website ______learners can not just learn
various languages but also chat online.
A.where
B.which
C.that
D.what
水溶液遇三氯化铁能显红色的是
A.维生素D3B.维生素B6C.维生素B2D.维生素CE.维生素A1