【一】It was his unenviable task to tell Karnazes that his sister，Pary, has been killed in a car accident.

=To tell Karnazes that his sister，Pary, has been killed in a car accident was his unenviable task 

解答：以上为不定式短语作句子真正主语，it为形式主语，that从句作不定式to tell的宾语成分，that从句谓语动词动作在不定式(to tell...)动作之前发生，所以要使用现在完成时态。Pary是his sister的同位语成分。

【二】At his thirtieth birthday party, drunk and contemplating marital infidelity, Karnazes abruptly walked out

解答：drunk可以有2个理解

【1】drunk是drink(vt.当作及物动词)的过去分词。作伴随/方式状语。

He had drunk himself unconscious on vodka.（drink及物动词用法）

他喝伏特加酒喝得不省人事。

【2】drunk是形容词“喝醉的” 作伴随/方式状语。

I got drunk and had to be carried home.我喝醉了，只好让人把我送回家。

She was too drunk to remember anything about the party.她喝得酩酊大醉，聚会上的事什么都记不得了。

At his thirtieth birthday party, drunk and contemplating marital infidelity, Karnazes abruptly walked out.

上面的句子可以转为下面句子

At his thirtieth birthday party,( he was drunk省略) and (he was 省略)contemplating marital infidelity, Karnazes abruptly walked out.