英文文法問題 10分

Computer systems have undergone 4 generations, based on the technology involved.
這句用了兩種的手法，第一種是關係子句省略法，即將what, that等的關係代名詞，並be（或它的變化，如：is, are, am等）都省略了，所以全句原為：
Computer systems have undergone 4 generations, which was based on the technology involved.
而第二種的手法，就是過去分詞修飾technology. technology involved可譯為有關的科技。
因要工作，稍後補答你的問題！

2007-08-11 10:52:15 補充：
SVOC其實是英文的基本句型，沒有甚麼特別，例子如：This made her happy.We elected him PresidentThey did not find it easy.I think it difficult等等

2007-08-11 10:58:49 補充：
confirmed sighting 是用了過去分詞confirmed作形容詞用，去修飾sighting這種的用法，confirmed sighting其實可以寫成：a sighting which was confirmed如用confirming sighting就等於a sighting which is confirming；confirm是確定，證實之意，a sighting並不可以自己確定（也因confirm並不是特質），而是被確定，所以，必須用被動式，這時候，也要用過去分詞。

2007-08-11 11:02:09 補充：
since then的意思是”自那時起”為甚麼可以這樣用？因為since不但可以作為連接詞，副詞；它也是介詞(preposition)在這裏的since就是作介詞用，如：I haven't heard from him since last year.（我自去年以來未曾收到過他的信。）介詞之後，要用名詞或名詞相等語，”then”在這句中，是名詞，是那時之意

Q1:句中based on the technology involved用了甚麼文法?
Ans: It is an adjective clause to further describe the situation of computer systems's development.

Q2 Ans: Subject= Computer systems
Verb= have undergone
Object= generations
Complement= based on the technology involved.

Good luck!!

2007-08-09 22:32:34 補充：
The system here has problems, which indicates I exceed the number of words even though I didn't, so I can't answer your question here.

2007-08-09 22:36:12 補充：
We use confirmed (Past Participle) to describe the noun (sighting) when we imply the action/situation is passive. In this sentence, "confirmed sightings" = "sighting that was confirmed by sb.(e.g authority)", so we use past participle to indicate this relationship.

2007-08-09 22:36:48 補充：
Since then = Since the previous action ( the last confirmed sighting of the baiji dolphin), you may chage the sentence structure as follow:Since the sighting of the baiji dolphin was confirmed five years ago, there have been unconfirmed sightings (but no sighting has been confirmed).

2007-08-09 22:58:32 補充：
In English, we usually avoid using the same words in a sentence. For example,1. I eat as much as John does ( "does" here = eat)2. I ran as fast as Sam did ("did" here = ran).Therefore, we use "since then" rather than repeat the same information.