positive
单词辨析：
指确定无疑的，表示说话人有确切的理由或不容置疑的证据，语气较强，通常作表语，多用于肯定句或正式的书面语中，常可与positive 换用，但不可单独用作回答。
He is absolutely certain/positive that he has met her before.
他绝对肯定他以前见过她。
She's not certain/positive when the movie will begin.
她不确定电影何时开始。
It is certain/positive that every effect must have a cause.
毋庸置疑，有果必有因。
He is certain/positive that the fruit is ripe.
他确信水果熟了。
指确信某事会以自己想要或期望的方式发生的，通常作表语。
They are confident next year's profits will be higher.
他们确信明年的利润会增加。
The French football team is confident of victory.
法国足球队对取胜很有把握。
The committee is confident of success.
委员会对成功很有把握。
指对某事深信不疑的，通常作表语，常后接介词 of 或 that 从句。
I am convinced that we are doing the right thing.
我确信我们做的事情是正确的。
I am fully convinced we can do it.
我完全确信我们能做这件事。
He is firmly convinced of the possibility of life on other planets.
他坚信在其他行星上可能存在生命。
指对某事物的正确性或真实性绝对肯定的，通常作表语，可单独用作肯定回答，常后接介词 about/of 或 that 从句。
She is absolutely positive that she opened the window.
她绝对肯定她开窗户了。
He can't be positive where he lost his key.
他说不准是在哪里丢的钥匙。
-Are you sure about that?
—-那事你能肯定吗？
-Positive.
—-能。
We'll benefit from this deal -I'm positive of that.
我们会从这笔交易中赚到钱的，对此我有把握。
指主观上对某事物的正确性或真实性没有疑虑的，常可与 certain 换用，但语气稍弱，通常作表语。
I am sure/certain that he is honest.
我肯定他是诚实的。
Are you sure/certain that this is the right road?
你肯定这条路对吗?
He wasn't sure/certain whether he would be able to get back as planned.
他不能肯定他是否能如期回来。
指有利于某事发生或成功的。
This plant will produce fruits under favourable conditions.
该植物在适宜的条件下会结出果子。
Bacteria multiply quickly under favourable conditions.
细菌在适当的条件下繁殖很快。
The company has made a huge profit in an international environment that is favourable to overseas investment.
在有利于海外投资的国际环境下，这个公司获得了巨额的利润。
指对某人、某种情况等有好处或有帮助的。
This contract is advantageous to the owners.
这份合同对业主有利。
You'd better be more cautious, as your rival is in an advantageous position.
你的对手现在处于有利地位，所以你最好更谨慎一些。
指积极的、良好的或有所助益的。
These vegetables have a positive effect on people's health.
这些蔬菜对人们的健康有好处。
Studying overseas has been a positive experience for him.
海外留学对他来说是一种有益的经历。
相关例句：
He was stripped of his Olympic title after testing positive for anabolic steroids.
在促蛋白合成类固醇检测呈阳性后，他被取消了奥林匹克冠军头衔。
Children who have a positive self-image are less likely to present behaviour and discipline problems.
自我感觉良好的孩子较少出现行为和纪律上的问题。
I'm as positive as I can be about it
我对它有绝对的把握。
There was no positive evidence that any birth defects had arisen as a result of Vitamin A intake.
没有确凿证据证明，摄取维生素A会导致出生缺陷。
We need a positive programme of crime prevention.
我们需要制订一个能有效预防犯罪的方案。
I think there are many positive aspects to being a twin
我认为身为双胞胎中的一个有很多积极方面。