课文详注 Further notes on the text

1.A perfect alibi
(标题)极好的不在犯罪现场的证据

alibi为法律用语,含义是“不在场证明”、“当时不在场的申辩”,是可数名词:
Ian had an alibi/alibis for that morning.
伊恩有那天上午不在场的证据/证明。

与它搭配的动词通常有offer, prove, set up等。

2....I was there on time...
我是按时到了那儿的。

on time为固定短语,表示“准时”、“按时”(注意它与in time的区别):
Can you arrive on time?
你能准时到吗?

Tom is never on time. He always keeps other people waiting.
汤姆从来不准时。他总是让别人等。

3.And you didn't notice anything unusual?
您没有注意到有什么异常情况发生吗?

这是一个陈述疑问句,即它具备与陈述句同样的基本语法结构,但用升调提问。这种句子在英语中不常用。不定代词如anything, something等被形容词修饰时,形容词必须跟在不定代词之后:

This is something special.
这很特别。

This isn't anything important.
这并不重要。

I'd like something cheaper.
我想买点较为便宜的东西。

4.I suggest…that you are not telling the truth.
我提醒您……您讲的不是实话。

I suggest (that) …在这里用于提出质疑,译为“依我看……”、“恐怕……”:
I suggest that he is not so honest as he looks.
依我看他并不像他看上去那么诚实。

I suggest that the car crash was not accidental.
恐怕这起汽车撞车事故不是偶然的。

5.You see, on the morning of the murder, the 8 o'clock train did not run at all.
你看,在凶杀发生的那天早晨,8点钟的那次车根本没有发。

(1)you see在口语中经常作为插入语出现,句首、句中或句尾均可以,表示“你知道”、“事实上”等含义:
He was not really interested in the film, you see.
事实上,他对那部电影并不是真的感兴趣。

My leg isn't all right yet, you see, so I can't climb the hill with you.
你知道/你看,我的腿还没有完全好,所以我不能和你(们)一起爬山。

(2)run可以指火车、公共汽车、船等“定时/定期行驶”、“(在两地间)往来”:
Buses run every ten minutes here.
这里的公共汽车每10分钟一班。

This ship runs between Dover and Calais.
这条船来往于多佛与加来之间。