Ⅰ.用方框中所给单词或短语的适当形式填空
1.Bob, you are really a ____________ to do such a silly thing.
2.Each of us is supposed to ____________ the environment.
3.The radio said a monkey ____________ from the zoo last Friday.
4.Tigers are ____________ animals. Many people are afraid of them.
5.I ____________ very late yesterday morning. So I was late for class.