1．complete v．完成→completion n．完成，结束→completive adj.完整的→completely adv.完整地，完全地
2．design v．设计→designed adj.设计好的→designer n．设计师
3．harm v．伤害，损害→harmful adj.有害的→harmless adj.无害的
4．agriculture n．农业→agricultural adj.农业的
5．prevent v．阻挡，防止→prevention n．预防，防范
6．harmony n．融洽相处，和谐→harmonious adj.和谐的
sheet n.床单，被单； 一张(通常指标准尺寸的纸)；(冰或水等的)一大片
①Be cautious！The road was covered with a sheet of ice. 一大片
②How often do you changed your sheets on the bed to keep clean？
床单
③Please write down your names on this sheet of paper，will you？
一张
