The paragraph is followed by an incomplete phrase or sentence which summarizes the main idea of the paragraph. Choose the missing words of the phrase or sentence. 

There are 15 million of us who fly across multiple time zones every year, with 500,000 of us in the air at any given moment. And for those of us who fly more than a couple of time zones from home jet lag can be a serious challenge.
Millions of people （） from jet lag every year.