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- I think there is a train about 12 but do not know for certain. 我想12點有一班火車，但我沒有把握。
- I think there is a train about12 but do not know for certain. 我想12點有一班火車，但我沒有把握。
- In such conditions, we could be face to face with a unicorn and not know for certain what it was. 雖然，麟之出，必有聖人在乎位，麟為聖人出也。聖人者，必之麟，麟之果不為不祥也。
- I do not know for certain. 我確實不知道。
- Do you know for certain what will happen to him ? 你肯定他會碰到什麼事嗎?
- He may succeed,but I don't know for certain. 他也許能成功，但我不敢肯定。
- We don't know for certain when it happened. 我們不能肯定是在什麼時候發生的。
- We may succeed,but I can't know for certain. 我們可能成功，但我不敢說肯定成功。
- I don't know for certain when he will come. 我無法確定他什麼時候回來。
- It's too soon to know for certain. 現在還太早， 不知道確切情況 。
- Only thing I know for certain is. 我唯一明確知道的一件事情是。
- I know for certain that it will rain tonight. 我確知今天晚上會下雨。
- He may succeed, but I don't know for certain. 他也許能成功，但我不敢肯定。
- Only the Fates know for certain. 只有命運才了解。
- Anon is not known for guile or intricate schemes. 阿農從不耍陰謀詭計。
- We never knew for certain how it happened. 究竟是怎麼發生的，我們始終未搞清楚。
- Nobody knows for certain what kind of man he is -- he's rather a lone wolf. 誰也不知道他是什麼樣的一個人--他總愛獨來獨往。
- I didn't know for certain where I should go at that time. 那時，我的確不知道該到哪兒去。
- Has not known for certain the rational number 未確知有理數
- And you can see the difference today: he's not known for talking in platitudes. 在現在你就能看出差別：他並不是以那些垃圾話而出名的傢伙.;(學文化好啊！
