A model or an experiment in a science class can help students see things which would ______ remain hidden.
The boy, _____ leg was injured in the football match, was only 11 years old.
They work day and night; however, _______ of the money they make goes to their so-called eldest brother.
The one and only thing I ____ is whether you take a good rest!
— Is there anything you want to know? — I just wonder ____ that makes Jim so excited.
She says she still remembers the things and the persons ______ I told him last year.