Learning to write is learning to think. You don’t know things clearly _______ you can write them down.

There's a red car parking in our neighborhood. Do you know _____ it is?

– Will you come to the wedding party? – I won’t come       Jenny          .

 ---Look! Such heavy traffic!--- I doubt _________ or not I can get to school on time.

The shops were closed,          I didn’t buy anything.