Everything is carried to a certain door, which forms the one connection.

"I had a hard time getting into certain doors in Hollywood," he said.

Finally, however, he stopped in front of a certain door.

"It is like having the keys to fit certain doors that not all of us get a chance to look in."

On the fourth floor, a certain door stood open.

He brought the room key with him, and made certain the door was locked.

Crossing the room, she made certain the door was locked.

She made certain the door was secured, then preceded the three men down the hall.

I think there is a definite chance that this book may close certain doors for me.

When they came to a certain inner door the wolf told the Prince to remain outside, while he went in.