Having checked the doors were closed and ______ all the lights were off, the boy opened the door to his bedroom

The car accident happened _____ his car wasout of order ___ I can’t drive.

Many new workers _____ trained and in two months they will _____ to build a new railway

The iPhone 4S is Apple’s first major hardware on the market ______ the Oct．5 death of co-founder Steve Jobs

we cannot leave this tough job to a person_____.