Answer:
It will shrink and collapse.
Explanation:
In the given question it is given that a thin-walled plastic bottle, which is sealed at a height of 19000 feet is carried down to 1000 feet. At an altitude of 19000 feet, the air will be colder, and at the same time, the pressure would be decreasing. Thus, if the bottle is carried down to 1000 feet, the pressure will increase resulting in the collapse and shrinking of the plastic bottle.