建设项目的固定性，设计的单一性，施工的单件性，管理组织的一次性，使得它不同于一般商品

根据对话内容，从对话后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。
— Hello, Mr. Black.    1  
— Yes, that’s right. Tomas, I counted the workbooks.    2  
— Err, Mr. Black. I think I forgot…
— Forgot? Students should know what they should do.
—    3   I swear I won’t make this happen again, Mr. Black.
— Are you sure? I’d like to believe you once.    4  
— Yes, I know. I will make up my undone assignment and submit it to you.
—    5  Remember to hand in your assignment punctually.

A. That will be fine. B. I am so sorry for that. C. Then do you know what you should do next? D. Are you looking for me? E. Why don’t you hand in your assignment on time? F. All are here except yours. G. May I come in?