从系统视角来看，工程项目管理是以（）为对象的。

A.项目

B.经济效益

C.可交付成果

D.完成项目组成部分的行动者、原材料和设备等

The early pioneers had to      many hardships to settle on the new land.

A．go into

B．go along with

C．go back on

D．go through