苯、甲苯、二甲苯都属于（）。
A.石油溶剂
B.酯类溶剂
C.煤焦溶剂
D.酮类溶剂
参考答案：C
People generally think that fairness and justice are at the centre of ______ they are striving for.
A．how
B．why
C．which
D．what
道岔的定位，应在何规章内记明？
