防御工事 /fángyù gōngshì/ angolul

fortification [fortifications]▼(the act of fortifying)
noun
[UK: ˌfɔː.tɪ.fɪˈk.eɪʃ.n̩] [US: ˌfɔːr.tə.fəˈk.eɪʃ.n̩]