加氢催化催化剂的活性组元以（）状态存在时活性才较高。
A.氧化物
B.硫化物
C.还原态
D.氯化物
参考答案：B
-----Can I ask you a few straightforward questions about yourself?
------No problem. I like______ when people are open and direct.
A．that
B．this
C．it
D．them
说明列车漏电的查找方法？
