問題詳情:
改錯:(2019·全國卷Ⅰ改編)Modern methods of tracking polar bear populations are expensive performing consistently over a large area.
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【回答】
performing→to perform 此處是“主語+be+adj.+不定式”結構,不定式用主動形式表被動含義。
知識點:非謂語動詞
題型:選擇題