小题1:The information about the 2012 European Cup is ______ (可获得的) on these websites.

小题2:The police thought there may be more _______ (原因) of the accident, so they kept on searching for clues.

小题3:_______________ (无论如何), I won’t give up trying until the end.

小题4:Some parents don’t realize that ________ (比较) their children with others’ is not good for their own children’s growth.

问题提出：在日常生活中，我们慢慢咀嚼馒头时会觉得有些甜，那么“馒头变甜与唾液的分泌有关吗？”请按右表所示的探究方案完成填空．

（2）实验结果：两支试管滴加碘液后，②______．

（3）得出结论：______．