they have done what they can__(help)the childrenin poor area

they have done what they can__(help)the childrenin poor area 一道英语题关于宾语从句they have done what they can__(help)the childreni what have they done with the meat?they hav [ ] have they done [ ] the spy what they have done __useful to the people Have they done what they can _____(stop) the environment pol They have done what they can (.) us stop the sangstorm.补空 Have they watered the flowers______ Yes,they have done it___ They have done all they could "to help" him.为什么是"to help"? They _____ help the children ____ poor areas in China. They did what they could____the poor children.为什么填to help 不填 judging from what they have done in the past few years.请问这个w