Not until I came home last night _____to bed.

     private cars are bringing us convenience, they may also cause traffic accidents and pollution.

—I often see him working hard in his spare time. —________he has won the scholarship from time to time.

I would appreciate     very much if you could send me a few copies of the mechanic design of your new model. 

I was leaving the office when it suddenly 　　　 to me that I had forgotten my keys.