根据下面的汉语用英语写一段情景对话!（六句话左右）你今天要去你同学家,首先向妈妈请示,妈妈开始不同意,你告诉妈妈你赶8点半按时回家,妈妈同意了并给你大门钥匙.

U:Mum,I'm going to my class' s home.Can you give me keys?
M:What?Do you finish your homework?
U:Er...I will do it tonight.And I promise I will be home at eight thirty.Please?
M:OK.You‘d better be home on time.Have fun.

A:Mum,can I go to my classmate's home?
B:Sorry,you can't.
A:Why?
B:I'm afraid of your safety.
A:Oh.Don't worry.I'll be back before half past eight.
B:OK.Here is the key of the door.
A:Goodbye,mum.
B:Bye!