Come and see me whenever ______.
53. If you want to change for a double room you’ll have to pay ___$15.
54. We should always keep ______ well-informed of the changing information.
55. Give the message to ______ is at the table.
56. I found _______impossible for _______to work out the maths problem.
57. Few pleasures can equal _____ of a cool drink on a hot day.