be certain about

We can only guess ( ie We cannot be certain about ) what happened.

我们只能猜测发生了什麽事.

By use of the basic formula of chemical thermodynamics and according to the stabilizing conditions of binary solutions at critical points, two equations of critical state which can be used to make certain about the form of binary solution, critical temperature and critical points have been derived.

利用化学热力学的基本公式，根据二元溶液临界态的稳定条件，通过数学推导，得到了两个可以用来确定二元溶液临界温度及临界点组成的临界态方程。

As it is virtually impossible to be certain about the ingredients of some products we have introduced a'potentially toxic'category.

因为事实上，不可能确定某些我们所引入的“具有潜在毒性”种类产品的成分。

But they cannot be certain about how a judge might assess their conduct.

但他们不可能确定法官可能会如何评估自己的行为。

We can't predict with certainty what the future will bring, but we can be certain about the issues that will define our times.

我们不能确切地预测到未来将会如何，但我们能够确定的是哪些问题将决定我们的时代。

You may be more certain about its meaning.

你们可能就清楚这个句子的意思了。

I'm afraid I can't be certain about that until next week.

恐怕要等到下星期我才能确定。

You can be certain about making a new friend as you find you are not the only person cheering after that magnificent goal.

当你发现不只是你一个人在为某个重大事件加油的时候，你也能认识一些新朋友。

Professor: As with most ancient history, there is not much that we can be certain about.

正如大多数古代史一样，我们能肯定的内容不多。

Be certain about what you believe and consistent in what you say.

你相信什么，就要坚定不移；你说过什么，就要言行一致。

It's difficult to be absolutely certain about some of the other stones, because after the execution of Charles I, Cromwell had the crown jewels broken up and sold.

一些其他宝石的渊源已难以考证&因为在查理一世被处决之后，克伦威尔曾将王室珠宝销毁并变卖。

I am afraid I can not be certain about that.

恐怕此事我不能肯定.

Assure sb/ oneself ( of sth); cause sb/ oneself to be sure or feel certain about sth

使某人[自己]对某事物确信不疑或觉得肯定无误

Only understanding where the problems are can we be more certain about its trend of city development and reconstruction, and ultimately, make the city to develop in good order.

只有清楚的了解了问题在那里，才能明确今后的城市建设和改造方向，使城市保持有序发展。

Turkish officials may be certain about Mr. Gulen's actions and motives, but the nature of his movement has long confounded analysts and diplomats in Turkey, partly because the organization is opaque and individuals do not openly declare allegiance to it.

虽然土耳其官员也许对居伦的行为和动机深信不疑，但其运动的性质一直让土耳其的分析人士和外交官员困惑，部分原因是因为这个组织不透明，其成员不公开宣布效忠该组织。

Just to be quite certain about what's just been decided: I will be responsible for marketing surveys.

把刚才的决定再讲明白一点：我将负责市场调查。