题目内容：

根据所给首字母或中文提示写出正确形式的单词。

1.He is not old enough to understand how to               （操作）the machine?

2.Due to the lack of     （目击证人）, it is difficult to apportion the blame for the accident right now.

3.To my           （满意）,my daughter has done all the housework.

4.I was not in f               of what is being done here;in other words,I disagreed.

5.The river is four metres in d               .

6.Nowadays, you can see many students wearing glasses because of bad e               .