Excuse me,can I sit here?
_____.The old man who sat here will be back soon.( )
You're welcome.
Yes,please.
You'd better not.
No problem.
Be quick, we’ll be late for the meeting.
I still remember my first teacher __________ we haven’t seen each other for many years.
They have been friends __________ they were at primary school.
I’ll go to visit my uncle in England ________ the winter holidays start.
The mobile phone has changed people’s life a lot ________ it was invented.