we should work as hard as we can---(help) the childen in nee

to help
这是一个省略句,此处省略了work.当从句谓语动词和主句的谓语动词相同时,可以省略.原句应为we should work as hard as we can work to help the children in need.其中,to help the children in need不定式结构作目的状语.