Question

if the underlined word or word group can be omitted without loss of meaning, click on omit. if the word group is required for the meaning of the sentence, click on keep. the humidifier put out a constant supply of moist air that never seemed to stop. omit keep

Explanation:

The phrase "that never seemed to stop" adds emphasis but is not essential for the basic meaning that the humidifier put out a constant supply of moist air.

Answer:

Omit