They failed to find out a solution to the problem.
=> They didn’t succeed ________________________________

He was sorry he hadn’t said goodbye to her at the airport.
=> He regretted ________________________________

 It takes six hours to drive from here to London.
=> It is ________________________________

We’ve run out of petrol.
=> There ________________________________

That was a silly thing to say!
=> What ________________________________

A man I don’t know told me about that.
=> I was ________________________________

People believe that the Chinese invented paper in 105 A.D.
=> Paper ________________________________

These young men became doctors after six years training.
=> After these young men ________________________________

 Because of the absence of the atmosphere on the moon, the sky there is black, just as in space.
= > Because there ________________________________

As people use a lot of wood-pulp, many trees are cut down.
The more ________________________________