________ seems to be no possibility _______ the shy girl can win the first prize in the contest. 

— Have you been to the Great Wall? —Perhaps not in my memory. ________, it might have been during my early childhood.

You can’t imagine what difficulty we had ________ home in the snowstorm.

Jack is ______go to school,so his mother has to stay at home to look after him.

 I _____not thank you too much for your help.