I just keep working hard as I have done, and ________ it will pay off. It has done so far and so I just have to do the same.

Ben has not the least_______ of giving up his research.

 If you lose a customer, regret it _____ excuse it, or you will lose him for ever.

It has been proved that taking exercise ________ does good to one’s health. 

The children loved their day trip，and they enjoyed the horse ride_____.