用方框中所给词或短语的适当形式填空。    

1. Are you _______ (confidence) of beating him?    

2. You should ask my _______ (permit) if you want to use my pen.    

3. —Mr Zhou is going to teach in Shcnzhen.        

    —Really? I don't know it in the _______ (slight).    

4. Our teacher was _______ (annoy) with us because we were not on duty.    

5. This problem is _______ (fair) easy to work out.    

6. I'm sorry _______ (bother) you.  Could you please help me fill in the form?    

7. Anna really wants _______ (keep)a pet dog, but her mother doesn't allow her to do so.    

8. If  I _______ (pass) the exam,  I would have a chance to travel to America.

简述起昙现象并分析起昙现象产生的原因。