1、expert

行家;专家

Our team of experts will be on hand to offer help and advice between 12 noon and 7pm daily.

每天中午12点到下午7点，我们的专家小组将随时提供帮助和建议。

a yoga expert.

瑜伽大师

技术娴熟的;熟练的;在行的

The Japanese are expert at lowering manufacturing costs.

日本人在降低制造成本方面很在行。

There is a great deal to learn from Hal's expert approach.

从哈尔熟练的方法中可以学到很多。

行家的;内行的

When the horse suffered a back injury Harvey cured it with his own expert hands.

那匹马背部受伤后，哈维用他内行的双手把它治好了。

The symptoms are very mild and it takes an expert eye to see them.

症状非常轻，要靠专家的眼睛才能看出来。

2、certain

肯定的;有把握的;毫无疑问的

She's absolutely certain she's going to make it in the world.

她坚信自己会出人头地。

We are not certain whether the appendix had already burst or not.

我们不敢肯定阑尾是否已经破裂。

必然的;必定的;肯定的

However, the scheme is certain to meet opposition from fishermen's leaders.

然而，这项计划一定会遭到渔民领袖的反对。

It's not certain they'll accept the Front's candidate if he wins.

即便来自阵线的候选人获胜，他们能否接受他还说不准。

确凿的；无疑的

One thing is certain, both have the utmost respect for each other.

有一点可以肯定，那就是双方都非常尊重对方。

It is certain that Rodney arrived the previous day.

罗德尼肯定是头天到的。