1.backbone n. 支柱；主干网；决心，毅力；脊椎

Agriculture forms the backbone of the rural economy.
农业是农村经济的基础(|*4kfI)o0p1H~4p(。

2.harvester n. 收割机；收获者

He was the man who invented the combine harvester.
他就是发明联合收割机的人2Qp.7O2yjX,。

3.child care 儿童保育

Both women had hired illegal aliens for child care.
两个女人都曾雇过非法入境者照看孩子u&Vi)=xy^VHaW6]ZvZ。

wvewC#x]3b)@FVDXLzb2q7Y.kupz*cr7Scyv]xPlW60)xg