I still remember ____ it was, he told me, ____ I could solve this kind of problems.
The elderly need special care in winter,as they are________to the sudden changes of weather.
He told me that nobody else in the office had received an ___________to the party.
Her _________to the job left her with very little free time.
I think at the beginning of each book a __________ introduction to it is necessary.
In _________to being used in industry,laser can be applied to operations in the hospital.