英语翻译直到她看到顶楼冒烟才意识到即将来临的危险(Notuntil,aware)在过去的几年里,这家工厂用塑料代替木材来降低成本.（substitutefor)

Question

英语翻译
直到她看到顶楼冒烟才意识到即将来临的危险(Not until ,aware)
在过去的几年里,这家工厂用塑料代替木材来降低成本.（substitute for)

Answer 1

Not until she saw the smoke on the top building did she realize the coming danger.
During the past few years,this company have been using plastic as substitute for wood to cut down the cost.