( )计算结果越大，表明其投资经济效果越好。
A．盈亏平衡点B．借款偿还期C．投资回收期D．财务内部收益率
参考答案：D
We've had a good start, but next, more work needs ________ to achieve the final success in English study.
A．being done
B．do
C．to be done
D．to do
目前用户局域网内部区域划分通常通过Vlan划分实现
