This morning, I rushed to the library, only ________ that its door was still locked.
The writer was always looking for suitable _____ to use in his next story.
I shall take you back to Beijing _____ you are well enough to travel.
Our house is the most _____ one in the street; it is painted red.
. It has been laid down that each student must _____ a composition to the teacher once a week.
Radium salts, which have been found to _____ in bones, give rise to cancers of the bone.