I can't be positive about what time it happened.

我说不准这事是什么时间发生的。

《牛津词典》

Can you be positive about what you saw?

你能肯定你看得真切吗？

《新英汉大辞典》

Be likeable and enthusiastic; don’t moan about your old boss, be positive about this new company.

在面试中表现得开朗和热情，不要抱怨你之前的老板，对新公司要显得正面积极。

youdao

"Well,I think the message from the United States personally coming here will obviously be a positive impact,in the sense that President Obama's administration is deeply concerned about the displaced people,".

VOA: standard.2009.06.03

One major difference between electron affinity and ionization energy is that when we talked about ionization energy, remember ionization energy always has to be positive.

电子亲和能,与电离能之间最大的不同就在于,当我们提到电离能的时候，记得电离能总是正的。

麻省理工公开课 - 化学原理课程节选

It turns out that it's going to be a little bit different when we're talking about positive ions here.

结果是当我们讨论阳离子时,有一些不同。

麻省理工公开课 - 化学原理课程节选

"There's not a whole lot to be positive about now, " said Cleveland Rueckert, an analyst at Birinyi Associates.

FORBES: Magazine Article

Quite how successful Kent have been in recent years is perhaps open to debate, what is not is that the county has plenty to be positive about.

BBC: Jones hopes Kent can bounce back

Overall Aung San Suu Kyi appeared to be cautiously positive about recent developments in Burma.

BBC: Aung San Suu Kyi cautiously positive on Burma reform