2. i think that that that that that student wrote on the blackboard was wrong.我認為那個學生寫在黑板上的那個“that”是錯誤的,引起賓語從句;第五個that是指示代詞“那個”;第三個that在這兒相當于名詞;第四個that是關系代詞,3. i know. you know. i know that you know. i know that you know that i know.我知道,我知道你知道,第四個trouble是