单选题The city was difficult&nb

问题补充：

单选题Thecitywasdifficult________,_________wasdefendedbyanarmyof6,000men.A.to be taken; whichB.to take; thatC.to take; whichD.to be taken; that

答案：

C解析The city was difficult to take = It was difficult to take the city. 只要这两种句型能够互换，不定式就得用主动的形式。