When did you know the news— I knew nothing about it _________ myfriend told me.

Paul invited us to take part in a party tomorrowevening.— ______ Is tomorrow his birthday

agara Fall is great tourist _______,drawing millions of visitors from all over the world every year.

In such a fierce competition, a person has to make every effort if he________[ ]

Are you sure ____ you have seen this man?—Yes, I’m quite sure ___that.