Emergency preparedness is no longer the sole concern of earthquake prone Californians and those who live in the part of the country known as "Tornado Alley." For Americans, preparedness must now account for man-made disasters as well as natural ones. Knowing what to do during an emergency is an important part of being prepared and may make all the difference when seconds count. source: http://www.ready.gov/america/beinformed/index.html Here the phrase "account for" confused me a bit, it is explained in http://www.thefreedictionary.com/account+for as blow: account for 1. To constitute the governing or primary factor in: Bad weather accounted for the long delay. 2. To provide an explanation or justification for: The suspect couldn't account for his time that night. With 1., the sentence is explained as:"preparedness must now constitute primary factor in man-made disasters as well as natural ones." With 2., it is:"preparedness must now provide an explanation for man-made disasters as well as natural ones." Neither of them makes sense to me, can anyone help me on this sentence? Thank you!