As new threats are posed by an unstable Russia and an increasingly confrontational China, American leadership is needed.
Special problems are posed by an author's second thoughts, whether preserved in his books and papers or incorporated in editions revised by him; recent research has shown that authorial revision in modern printed books has been underestimated.
Easily the most poignant issue was posed by a Wecolator chair lift on the stairway.
Earnest and respectful, he considered the question as if it had been posed by a teacher.
The wardens' biggest challenge is posed by a particularly fearsome six-legged creature: man (or woman) and dog.
Mr. Obama passed on the boxers-or-briefs question earlier this year when it was posed by a reporter for US Weekly.
"Who arranged it the way it is," he demands, "and when?" This is an intriguing if unlikely question to be posed by a man like Gerard.
After months of testing, they concluded that the greatest threat to "David" was posed by a light sprinkling of gypsum, a calcium sulphate that responds to humidity.
On a personal level, I warned the Ministry of Defence several years ago of the dangers to aviation that could be posed by a major Icelandic volcanic eruption.
The city agency said a more serious, long-term problem would be posed by a substantial reduction in the city's surplus because of Congressional cuts.
