技巧 l 如果选项中出现了与完成时态有关的时态，这个选项一般说来是正确答案。 l 如果选项中出现了被动语态，与主动语态相比较，被动语态一般是正确答案。 例句 例句1. Professor Williams told us that by the end of this year he ______ here for two years. ⊙A. will have worked