再生障碍性贫血的发生机制为（）
A.骨髓造血功能低下
B.红细胞破坏
C.急性失血
D.严重感染
E.造血原料缺乏
参考答案：A
--I hear you __________ your project at the end of last week.
--In fact, I __________ it by the end of last month.[ ]
A. had finished; had finished
B. finished; had finished
C. had finished; finished
D. finished; finished
在测算资本金融资成本时，其资金占用费是按( )计算的。
A．综合利率 B．贷款利率C．折现率 D．机会成本
