United States does NOT require the life preserver to be made ______.

参考解析：

推理判断题。根据最后一段第一句“The method of adjustment to the body should be simple, and self-evident to uninitiated persons even in the dark under the confused conditions, which follows a disaster.”可知，调整身体的方法应该是简单的，而且对于没有经验的人来说是不言而喻的，由此可推测救生衣穿戴比较简单，两边都能穿，所以A项正确；根据第二段最后一句“Thus it should be made of materials resistant to sunlight, gasoline, and oils, and it should be not easily set on fire.”可知，救生衣应该由耐阳光、耐汽油和耐油的材料制成，而且不容易着火，所以B项正确；根据最后一段最后一句“A suitable life preserver also be comfortable to wear at all times, in and out of the water, not so heavy as to encourage to take it off on shipboard while the ship is in danger, nor so burdensome that it hinders a person in the water while trying to swim.”可知，一个合适的救生衣也应该是穿着舒适的，无论在水里还是在水里，不要太重以至于在船处于危险的时候鼓励把它从船上取下来，也不要太重以至于它阻碍了一个人在水里游泳，所以C项正确；根据最后段第四句中的“In addition, the life preserver must be adjustable to the wide variety of shapes and sizes of wearers”可知，救生衣必须可根据佩戴者的各种形状和尺寸进行调整，所以尺寸并未根据落水人来设计，D项错误。故选D。