物业管理成本按照与决策的关系划分中,( )成本是指因为过去决策已发生,而在目前和未来无论实行何种方案均无法改变的成本。
A.边际B.沉没C.可免D.附加价值
参考答案:B
I had my bike ______ yesterday. It was broken. [ ]
A. repair
B. repairs
C. repaired
D. repairing
外生成矿作用