进行寿命周期成本评价时（）。

A．不需确定寿命周期成本的各要素

B．需将设置费和维持费两者进行权衡

C．需从寿命周期成本和系统效率的关系角度进行研究

D．需对费用发生的时间顺序加以掌握

E．可不考虑“资金时间价值”

. Mother has been busy packing my belongings, making sure I have everything I need. It feels as if she ____ to college with me.

A．were going

B．had gone

C．would go

D．has gone