What terrible thing happened to Mr. Dahl while serving in the Royal Air Force

Laugh and be merry, remember, better the world with a song,    better the world with a blow in the teeth of a wrong.    laugh, for the time is brief, a thread the length of a span.    laugh and be proud to belong to the old proud pageant of man. (laugh and be merry/john masefield/public domain) which of these is the main idea of the poem?

The significant structural shift that happens between chapters 21 and 22 is

Strategies garrett hardin uses to develop his ideas in lifeboat ethics an how they contribute to his overall point