不能肯定的

However, effects of technical progress and uncertainty exert ambiguous influences, which can either increase or decrease abatement costs.

技术进步和不确定性等的影响则不能肯定，可能会导致减排成本的上升或下降。

Affectation is inevitably the mark of one not sure of himself.

避免的会暴露不能肯定自己的人。

It sounded like the noise was coming from my parents bedroom but I couldn't be sure so I just listened with full attentiveness.

它听起来像噪音是来自我父母的卧室，但我也不能肯定，所以我刚才听到充分的专注。

I expected Steve to be in the children's ward but he was in a room by himself, because the doctors wanted to study him, and also because they weren't sure if what he had was catching.

我期望史蒂夫在儿童病房里，但他独自在一间病房，因为医生们要观察他的情况，也因为他们不能肯定他的病是否会传染。

But I'm not sure you're correct about that.

但我不能肯定你说的是对的

I'm not sure what I just said, but you get the drift...

我不能肯定我说的是对的，但是你也晕乎乎了

The duplicitous nature of Ming was played so well by Lau that by the last scene, you are still not sure whether he truly wants to be good, or was it all just an act that he has perfected?

刘德华把刘健明的双重性格演绎得如此之好，以致于直到最后一个镜头，你都不能肯定是他真的想做一个好人，又或者这一切不过是他漂亮的一出戏。

We may use 'should' in the if-clause if we are not sure about the possibility.

如果我们不能肯定句子的可能性，可在子句中加'should'。

We may use 'should' in the if-clause if we are not sure about the possibility.

如果 们不能肯定句子的可能性，可在子句中加'should'。

Nor could he be certain who knocked down the shell that remained, although he noted that Doohan owned the only heavy construction equipment on the island.

他也不能肯定谁撞倒了外壳，尽管他指出，杜汉拥有该岛上唯一的重型建筑设备。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。