来源:学生作业帮 编辑:搜狗做题网作业帮 分类:英语作业 时间:2024/08/19 17:33:00
根据句子结构和句意用所给单词的适当形式填空.
They are said _(find)out a simpler method for producing plastics.
准确答案应该是:to have found
解释:不定式短语to find out...所表示的动作发生在谓语动词are said之前,所以使用其完成形式to have done sth,所以答案是to have found...