Pls explain grammer of this sentence:

其實答案是非常簡單，這段是引自CNN.com
但之前有一段文字你可能忽略了，這段文字是”THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.”
Rush Transcript是指匆忙的錄音的文字記錄，所以是有可能出現遺漏
而你的示句全句是：
That's the usual scene, which makes the scenes in a couple of courtrooms today most unusual. In one a very rich Martha Stewart listening to one of her good friends testify against her. And, in another courtroom, a very wealthy Jeffrey Skilling listened to charges that he was at the center of the Enron fraud.

其實若你仔細分析，大約，In one a very rich Martha Stewart listening to one of her good friends testify against her這句，漏了一個字was，全句應是：In one a very rich Martha Stewart was listening to one of her good friends testify against her.(全句意思是：在其中一個法庭上，鉅富Martha Stewart那時正聆聽她其中一個好友作證指控她）
希望這樣解釋你會明白！

非常好o既一點，你有俾上文下理。但敢問一句，有冇抄錯？
１．先講 in one，有埋上文下埋就好清楚。成段係講今日幾個 unusual scenes in courtrooms。In one 就係其中一個，同佢呼應o既係下一句o既 in another courtroom－－其實呢個 courtroom 係可以唔加o既。
２．跟住係 a very rich Martha Stewart。一個人我地如果知道名，係唔會用冠詞o既，直呼其名就得，但係如果要加入一ｄ形容，就可以講 a/an + adj. + name，如：
Tom is always calm. But an unhappy Tom can yell at everybody.
呢度o既 a very rich Martha Stewart 同 a very wealthy Jeffrey Skilling 都係咁用。
３．subject / verb / object
其實 In one a very rich Martha Stewart listening to one of her good friends testify aginst her 係冇左動詞。
睇句簡單ｄo既例：I heard him sing a pop song.
subject：I　　verb：heard　　object：him
而 sing a pop song 唔係動詞，而係一個 bare infinitive（亦可作 -ing form，但意思有異 ）。
再睇另一例：The boy sitting there is my cousin.
sitting there 係 participle clause，亦可作 defining relative clause who is sitting there o既簡化版，所以成句o既主詞係 The boy sitting there。
睇返原句，a very rich Martha Stewart listening to one of her good friends... 中，listening to one of her good friends testify aginst her... 成句都係 participle clause/defining relative clause。而如果將 testify 睇成動詞，咁第一 tense 錯（後句都用左 listened 啦），第二就有違粉紅色例句o既原則。所以其實係不倫不類。
最簡單o既改法，係：
In one a very rich Martha Stewart listenED to one of her good friends testify aginst her.
咁就同粉紅色例句o既原則吻合啦，同後一句 a very wealthy Jeffrey Skilling listened to charges... 亦呼應到。

2007-07-13 23:30:14 補充：
唔好意思，粉藍色部份唔多清楚，我括一括會好ｄ：sitting there 係 participle clause，亦可作 defining relative clause〔who is sitting there〕 o既簡化版

As I think, It is a correct sentence.

In one ( adverb )
a very rich Martha Stewart listening to one of her good friends ( subject )
testify ( verb )
against ( preposition )
her ( object )