black humour

Harry Potter and the Goblet of Fireの映画が昨年公開されましたが、それより少し前にRoald DahlのCharlie and the Chocolate Factoryもロードショー公開され、明日２月３日はDVDが発売されます。
どちらも「おとぎ話」あるいは「ファンタジー」という言い方もできる小説の映画化です。
Harry Potterは非常に話題になりすぎで、具体的な内容は出題しにくいようでこれはで作者の伝記に関する英文くらいしか出題されていなかったと思います。一方、Dahlの方は確かにファンはいますが、まだ限定的なようでここでは内容まで踏み込んだ英文の出題になっています。

では、実際に筑波大（２００１年）で出題された英文の一部を二つに分けて読んでみましょう。
まず「その１」です。
   The use of the word 'unexpected' in relation to many of Roald Dahl's short stories is quite common. The endings to his stories are often unexpected and take the reader by surprise. Sometimes the endings are comic, sometimes they are tragic, sometimes a likeable character wins,sometimes an evil and disliked character wins; in most cases, however, the ending is almost impossible to predict and there is a 'twist-in-the-tail'. Many of the stories are humorous as characters find themselves in unusual or extreme situations but the humour is nearly always a 'black' humour because comic and tragic elements mix together.

読めましたか？ここで 'twist-in-the-tail'とあります。この言葉をここで使われている別の語を使って表現してください。

さて、次は「その２」です。読んでみてください。ちょっと以下の部分は語り切れていないように思います。出典で確認したいところですが、読んでみてください。
   Black humour is an important element in Roald Dahl's writings. Dahl seems to enjoy treating some of his characters in a cruel way. The characters find themselves in circumstances which they did not expect or which have tragic consequences, but their situation is often described in an amusing way and readers find that they are laughing at the personal tragedies of the character and that they may even enjoy reading about their misfortunes. Black humour is directed at characters who are shown to be unsympathetic but is also sometimes reserved for characters we have grown to like. The starting-point for many of the stories is often everyday, common incidents of ordinary life and the characters are often people with whom readers can identify. Not one of Roald Dahl's stories could be called sentimental.

ここで言われている 'black humour'についてまとめてみてください。
なお、興味があれば問題の全文も読んでみてください。