It worried her a bit_______her hair was turning grey.
He appears ______ a long time. He is impatient for my arrival.
Every device ______in the plane must be designed and made with great care so as to make sure that nothing goes wrong in operation.
He left home early only______he was late as he went a wrong way.
— Beijing or Shanghai? What did you mean? — We were talking about _______ go to college.
When he was a boy, he used to go there and watched _______.