Mother: You don’t look happy, Cathy.       小题1:        

Cathy: I didn’t do well in the chemistry test.

Mother: Really? I could hardly believe you were not doing well in chemistry.             小题2:       What happened this time?

Cathy:    小题3:      I found all the questions easy and I finished the test in no time.

Mother: Yes. It is one of your weaknesses.

Cathy: Yes.      小题4:      I made some very stupid mistakes that I shouldn’t have made.

Mother:       小题5:       

Cathy: Yes, I have certainly learned a lesson.

A．I know you are very good at chemistry.

B．What’s wrong?

C．I was too careless.

D．I feel angry at it.E. You are right.

F. Well, next time you should be more careful.

G. I don’t know.

就燃烧室筒体来说，从内到外依次为（）、（）、（）和可压缩层（膨胀材料）。