is known to us all is the old scientist, for whom life was hard in the past, still works very hard in his eighties.
The man you referred to _____ just now.
How happy we are! The holiday we have been looking forward _______ at last.
You can never imagine what great difficulty I had ______ your house all by myself.
Who did the boss _____ his car this time?
Some kinds of animals can _______ the colour of their surroundings.