When deeply lost in thought, _______ he often was, he would forget all about eating or sleeping.
We agreed to accept ________ they thought was the best professor in the college.
I don’t know who invented ________ telephone. It’s really ________ most useful invention.
----Whose advice do you think I should take? ----________.
——Will you require anything else? ——Yes, I like a whisky.
What worried the child most was ______ to visit his brother n hospital.