probe a rumour的用法和样例：
- I heard a rumour (that) he was leaving.
- There's a rumour floating around of a new job in the unit.
- It is whispered(ie There is a rumour) that he is heavily in debt.
- A rumour about the manager was swirled in the firm.
- A rumour does not always prove (to be) a fact.
- There's a rumour going round that Sue and David are having an affair.