Sir, would you mind my sitting next to you—__________. My father will sit here in a minute.

He told me that he would remember the days in Beijing University forever____ he got much help there from Professor Zhu

We don’t have enough pens ,Give us .

the books onthe desk, ______ is of any use for study

No matter how frequently＿＿，the works of Beethoven still attract people all over the world.