( )，由经营成本、折旧费、摊销费、经营期财务费用构成。

A．财务效益估算

B．运营成本估算

C．建设投资估算

D．建设期利息与流动资金估算

—— It's no  easy task to catch a ticket on a website that receives l billion clicks daily．

一一I can’t agree with you more．There      be errors for every single step

A．should

B．must

C．can

D．will