阅读下面材料，在空白处填入适当的内容（不多于3个单词）或括号内单词的正确形式。
Are you facing a situation that looks impossible to fix？
In 1969, the pollution was terrible along the Cuyahoga River near Cleveland, Ohio. It _ 61 _ 　（be）unimaginable that it could ever be cleaned up. The river was so polluted that it　 _ 62 _ 　（actual）caught fire and burned. Now, years later, this river is one of 　 _ 63 　 _ most outstanding examples of environmental cleanup.
But the river wasn’t changed in a few days　 _ 64 _ even a few months. It took years of work _ 　 65 _ （reduce） the industrial pollution and clean the water. Finally, that hard work paid off and now the water in the river is _ 　 66 _ 　（clean）than ever.
Maybe you are facing an impossible situation. Maybe you have a habit _ 67 _ is driving your family crazy. Possibly you drink too much or don’t know how to control your credit card use. When you face such an impossible situation, don’t you want a quick fix and something to change immediately?
While there are 　 _ 68 _ （amaze） stories of instant transformation, for most of us the　 _ 69 　 _ （change） are gradual and require a lot of effort and work, like cleaning up a polluted river. Just be　 _ 70 _ 　（patience）.