Early in the ancient times, farmers did experiments(improve)______ the agricultu

游客2024-07-16 31

问题 Early in the ancient times, farmers did experiments(improve)______ the agricultural productivity.

选项

答案 to improve。

解析根据句子结构判断，空格处应为动词不定式作目的状语，所以空格处应填入improve对应的动词不定式形式to improve。

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Earlyintheancienttimes,farmersdidexperiments(improve)______theagricultu