21.   Even when a window of opportunity opens at the last minute, there are barriers in the form of premium prices for last-minute flights.

22.   Even if the recipient is not online, a window will open on the screen, signaling that someone is trying to get in touch.

23.   Everyone back then slept with the doors and windows open.

24.   Four large windows opened onto the street, the summer air circulated by a cooling fan.

25.   He also envisioned miniature motors that will enable windows to open, fans to spin, passengers to move around, and so on.

26.   Her stitching window opened right then and she was ushered into the emeregency room.

27.   Here, the windows open wide.

28.   His home, before dark and musty, now is brilliantly lit, its windows open to reveal the splendor of its surroundings.

29.   I prefer the windows open.

30.   I had the windows open and slept with all my might all night long.