【单选题】Read the paragraph below from the introduction [paragraphs 1-3]. The running buffalo clover vanished. That was when bison disappeared in the U.S. Scientists actually thought the plant was extinct. Thi...
【单选题】Read the following paragraph from the introduction [paragraphs 1-5] of the article. Hide-and-seek is hard. It is harder than something like playful wrestling. You have to know the rules to play hide-a...