Many died or returned home, but most remained in California to________a life for themselves in the

new towns or on farms. [ ]

A. make  

B. come  

C. bring  

D. lay

在( )环节，实现能量的梯级利用、资源的高效利用和循环利用，努力提高资源的产出效益。

A．资源消耗

B．资源开采

C．废弃物产生

D．社会消费