1.   As the doors slid open he glanced at the middle-aged couple who got out but then stared straight ahead again.

2.   The elevator doors silently slid shut.

3.   The lift doors slid open and we got in.

4.   The door slides along a groove in the doorframe.

5.   The lift doors slid open.

6.   The lift doors slid shut, then open again.

7.   As the doors slide open, a mural-sized photo of the Saturn V perched on its launch and bathed in a glorious Florida dawn is revealed.

8.   A plastic barrier will separate waiting riders from the track, its doors sliding open to admit them when the train has halted in place.

9.   A steel door slides out of the wall facing the living room and provides privacy for the master bedroom.

10.   Floor-to-ceiling doors slide back and forth to reveal a changing landscape.