Prof. Richard was crazy about his research. His illness_________ his many years of hard work and irregular diet.

Some kinds of animals can change their colour with _______.

in London, we paid a visit to thehospital founded__________the nurse Florence Nightingale

Who was it _______ wanted to see me just now?

Saving Private Ryan is _____ unforgettableanti-war film and also _____ story of courage and sacrifice..