辨一辨，组成词语。

杖____      渭____      咕____      憾____

仗____      谓____      估____      撼____

阅读下面材料，在空白处填入适当的内容（一个单词）或括号内单词的正确形式。答案写在答题卷上。
    Are you facing a situation that looks impossible to fix?
    In 1969, the pollution was terrible along the Cuyahoga River near Cleveland, Ohio. It ____ (be) unimaginable that it could ever be cleaned up. The river was so polluted that it ____ (actual) caught fire and burned. Now, years later, this river is one of ____ most outstanding examples of environmental cleanup.
    But the river wasn't changed in a few days ____ even a few months. It took years of work ____ (reduce) the industrial pollution and clean the water . Finally, that hard work paid off and now the water in the river is ____ (clean) than ever.
    Maybe you are facing an impossible situation. Maybe you have a habit ____ is driving your family crazy. Possibly you drink too much or don't know how to control your credit card( 信用卡) use. When you face such an impossible situation, don't you want a quick fix and something to change immediately?
    While there are ____ (amaze) stories of instant transformation(转变)，for most of us the ____ (change) are gradual and require a lot of effort and work, like cleaning up a polluted river. Just be ____ (patience)

移动一根火柴，使式子成立。

  

胎儿与母体交换物质的器官是（　　）

要使反射光线垂直于入射光线，入射角的大小为____；沙漠上空出现海市蜃楼是属于光的____（选填“反射”或“折射”）现象．