關於四個 passive voice 的「使用規則」

1) Present Perfect
以前開始/發生, 現在及將來都仍然持續.
e.g. The statue of our school founder has been located at the entrance since 1971.
2) Past Perfect
用作比較已發生的兩件事的先後次序, 首先發生的用 Past Perfect , 後來發生的用
Simple Past Tense
e.g. My lovely teddy bear had been stolen when I returned home last week.
3) Present (passive)
現在/剛發生
e.g. Mr. Donald Tsang is invited to be the special guest of our graduation ceremony next week.
4) Past (passive)
過去發生的
e.g. Hong Kong was occupied by Japan in World War II.

2007-01-26 13:28:41 補充：
The photo was taken by me. (我以前拍下的照片)

首先，你不應該覺得 passive voice 是有什麼特別「使用規則」 ，是沒有的
圖片參考：http://hk.yimg.com/i/icon/16/35.gif
，最重要只是看清楚句子要用那一個tense。請看下解釋。

has/have been + pp. 是 has/have + pp 的 passive voice；大家都是 Present perfect tense
had been + pp 是 had + pp 的 passive voice；大家都是 Past perfect tense
was/were + pp 是 簡單過去式 的 passive voice；大家都是 Simple past tense
is/are/am + pp 是 簡單現在式 的 passive voice；大家都是 Simple present tense
is/are/am + being + pp 是 現在進行式的 passive voice；大家都是 Present continuos tense

所以，你應該現在明白只要 tense 是一樣、應用時候亦會一樣，只是轉為被動型。
I ate an apple yesterday. 這是 simple past tense，所以轉做passive voice，亦必須用 simple past tense。 變成 An apple was eaten by me yesterday.
Tom had read the book since we met him. 前面是 past perfect tense，所以轉成 passive voice 時，便要用一樣的past perfect tense。變成 The book had been read by Tom since we met him.

你的問題：
The photo ______ by me (take)
因為沒有注明時間，是昨天、現在或明天，那只可以用 simple present tense，這個決定跟是否 passive voice 無關。
好了，現在決定了用simple present tense，再看句子，原來要用passive voice，因為 photo 不可能是 object (主題)，object 是 me，又見到 by me，所以明顯地這需要用 passive voice。
那麼，就用 simple present tense 的 passive voice 了：
形態是 is/are/am + pp，所以答案是 is taken








2007-01-26 13:11:32 補充：
對不起，沒有看到你的中文問題 ------- 如果那張照片是(被)我以前拍下的 , 但不知道時間，那就用 simple past tense 好了。所以答案應是 was taken.

The photo was taken by me
The photos were taken by me

如果那張 <~~~ That photo was taken by me
That 先係指定一張，如果translate應該唔會用the