根据句意,用所给单词的适当形式填空。We all know ______________ (pollute) water does harm to our health.
I have read five (twelve) of this book.
If you are in a blue mood, you can do your hobbies to cheer ( you) up, boys.
To tell you the (true), I felt sad while you were away.
The children heard the (frighten) shout and looked at each other in fear.